Back at the scene of the club's greatest ever night, Chelsea's return to the Champions League ended in a self-inflicted defeat.
Harry Kane may have scored twice, but Chelsea shot themselves in the foot by presenting Europe's deadliest striker with a penalty and a gift after Trevoh Chalobah had netted an own goal.
Chelsea famously beat Bayern Munich in their own stadium to win the 2012 Champions League, but it has been over two years since they have competed against Europe's best. They were handed a lesson.
Under the watchful eye of co-controlling owners Behdad Eghbali and Todd Boehly, who had both flown into Munich to be inside the Allianz Arena, Cole Palmer scored his first Champions League goal for Chelsea.
But Enzo Maresca's young team were punished for their naive errors and the Italian was booked in his first Champions League game as a head coach.
Most of Chelsea's danger had been going down Bayern's left, so it was a blow for the home side when left-back Josip Stanisic was forced off with an injury early in the second half. Sacha Boey replaced him and Laimer had to move from the right to the left.
Olise had been the outstanding player on the pitch in the opening 45 minutes and he produced a wonderful touch to help Bayern make their first meaningful attack of the second period. Kane eventually passed to Luis Diaz and his shot was straight at Robert Sanchez.
Sanchez then stood up well to brilliantly deny Kane, who had charged into the penalty area and shot low with his left foot from eight yards. Chelsea were even more thankful to Sanchez on the hour mark, when he produced an incredible save down to his right to stop Olise converting Kane's cross. The former Crystal Palace star will have wondered how he did not score.
But Bayern did not have to wait long for a third and it came courtesy of a terrible error from Gusto, who inadvertently played the ball straight into the path and this time Sanchez could do nothing to stop him scoring.
Palmer was denied what would have been a beautiful second goal after VAR ruled he had been offside before slotting the ball between the legs of Neuer and Jackson got on for the six minutes of stoppage time.
Chelsea can still be confident of plotting a successful path out of the league phase of the Champions League, but lessons will need to be learned if they are to go deep into the most unforgiving of competitions.
Harry Kane's two goals help Bayern Munich to victory over Chelsea who were given a harsh reminder of the margins that decide Champions League games. There was much to like about their performance, especially in the first half when Palmer and Pedro carried the fight, but they conceded three cheap goals which cost them any chance of a result. They looked what they are: full of mobility and talent but green. Benfica at home next is now a must win with Barcelona and tough trips to Italy on the way.
Nicolas Jackson is of course on now in place of Kane, and he tried to chip Sanchez from the halfway line after the ball was turned over on halfway.
Harry Kane and Serge Gnabry get a great ovation from the Bayern fans after they are substituted. There will be six minutes of added time to play.
He just started his run a little early and it did not take long to clear up with the semi-automated offside. Shame, it was a well-worked goal.
But is he offside? It was a lovely through ball from Andrey Santos to find him in the box, and he opened his body up to finish beyond Neuer, but he may have strayed with the initial run.
Bayern fans have started a chant to the tune of Auld Lang Syne. No sign of the usual rendition of Three Lions in perfect English. Chelsea are finishing with some fight, but Garnacho shoots straight at Neuer.
Glenn Hoddle makes the astute point (astute because I happen to agree) that Bayern have looked a lot better with Kim at centre-back than Tah.
Luis Diaz thought he was in for number four, but the flag goes up eventually for offside. No matter, Sanchez made another good smothering stop. The late flag results in a collision and a painful one for Diaz. Always annoying for players, that one.
Chelsea with a sustained spell of possession in the Bayern half, but the home team are holding them at bay quite comfortably. Chelsea have actually looked less threatening in this second half when they have had more of the ball. Estevao is coming on for Enzo Fernandez.
Lovely touch from Harry Kane to roll away from Chalobah and bring Bayern up the pitch but he did not quite have the pace to finish the move and fouled Enzo Fernandez. Estevao is about to come on for Chelsea. Chalobah is still down holding his shoulder.
Chelsea have a free-kick in a crossing position wide right after a rather soft foul on Gusto, but Fernandez's delivery was dreadful. Such a waste. Bayern look like they are cruising to a victory at their own pace. They will need some of their first-choice defenders back by the knockout rounds, though, if they are to be contenders.
Strong defending from Cucurella as Olise cut inside and looked for the shot towards the far corner. Chelsea come forward, but Palmer's inswinging cross from the right towards Garnacho is cleared.
Bayern have been better since Kompany's changes, and they almost had number four there with Michael Olise curling a trademark shot just wide of the far post.
Maresca makes a double sub: Andrey Santos and Alejandro Garnacho replace Reece James and Pedro Neto.
Chelsea have been enterprising going forward tonight, but there has been a softness and naivete in the three goals they have conceded. You can play well in general play, but you are done for at this level if you gift goals away.
Chelsea just needed to get through this sticky spell, but they have been architects of their own downfall. As they played out from the back, Gusto took a loose touch, was almost robbed, and went to ground only to poke the ball into Kane's path inside the box. Still plenty to do, and Kane whipped a shot through legs into the far corner.
This has been a strong spell from Bayern, but Chelsea get some respite thanks to an offside flag.
Another superb save from Sanchez when Olise looked certain to score. That was Bayern's best move of the match, a flowing move that started with passing across the back before they quickened things up down the right. Kane played a clever pull-back towards Olise towards the penalty spot, and Sanchez got down quickly to keep the side-foot shot out.
Big save from Sanchez to deny Kane! Tosin was a bit keen to get tight on the halfway line, and Laimer burst into the space beyond him. He played Kane in with a reverse pass, and he went for power with his weaker left foot. Sanchez spread himself and made the crucial stop. Good goalkeeping.
Chelsea seeing most of the ball so far in the second half, but suddenly they are back-peddling after Kimmich breaks forwards. Bayern worked the ball across the Chelsea box but Luis Diaz could only shoot straight at Sanchez. Then Gnabry makes a foul to stop a Chelsea break.
The Cole Palmer nutmegs Laimer. Chelsea need to target the left side of that Bayern defence.
Joao Pedro impressing again with his link-up play, but James scuffed his effort from range and it was easy for Neuer. It has been a positive start to the half from Chelsea. It looks like Boey is playing at right-back with Laimer, a natural central midfielder, playing at left-back. Opportunity knocks for Chelsea.
Stanisic tried to carry on after taking the whack, but is going to come off. Looks like he might have hurt his shoulder. Boey replaces him at left-back, the former Galatasaray full-back. Chelsea should keep feeding the ball down that side.
Chelsea thought Gusto was in down the right after Caicedo's chipped pass over the top, but the Bayern defence had pushed up and he was caught offside. Chalobah with a thumping header, but the referee stops play after Stanisic comes off worse in the duel.
Chelsea get the second half started at the Allianz Arena.
Kim has replaced Tah at centre-back in a like for like change. If no injury, Kompany has hooked his central defender who was on a booking. He struggled against Pedro.
Plenty to be encouraged by if you are a Chelsea fan. They have been awkward opponents for Bayern, who have struggled to move through the gears even if they lead. Joao Pedro is proving elusive for Bayern's two centre-backs Tah and Upamecano and Chelsea keep finding space down their right flank through Palmer and Gusto. Bayern have threatened from the same zone; Olise has been the pick of the bunch for the home team. I suspect Kompany will have the harsher words at half time.
One last Bayern corner for Chelsea to defend. Who won it? You guessed right, it was Olise. Sanchez claims, but there was a foul in any case.
There will be two minutes of stoppage time at the end of the first half.
Enzo Fernandez should have done better there, was so much space for Palmer to receive on the right but the midfielder dragged his pass through to Neuer. Bayern come forward again, and their main outlet Olise wins a corner.
Another Bayern corner, punched clear from Sanchez, but met on the volley by Olise but despite the Chelsea goalkeeper diving for the cameras it was always spinning wide of the far post. Not his cleanest strike.
Michael Olise looks Bayern's best player; another delightful pass scooped into the box for Harry Kane who takes the shot on the bounce from a tight angle and it is deflected behind for a corner. Taken short, but the delivery is poor and Chelsea head clear.
Despite struggling in so many phases of play, Bayern still look a menace when they do attack. Buetifully weighted pass from Olise to find the underlap of Laimer, but the right-back poked his shot just wide of the far post.
Lovely interplay from Chelsea through midfield involving Caicedo and James, but Neto could not quite cast the ball under his spell on the left flank. Chelsea have looked capable of cutting through Bayern for most of the game. After another burst forward from Gusto, Neto blasts over from just outside the box.
Chelsea did not deserve to be 2-0 down, so that Palmer goal is just rewards. In the build-up to Palmer's goal there was an arm across the throat to halt Joao Pedro and the Chelsea bench were furious there was no further punishment. Joao Pedro then produces and silky touch to get Chelsea moving forward.
That is a beautifully executed goal to get Chelsea back into this. Bayern's midfield pressed forward trying to nick the ball high up, and there was so much space left behind for Palmer to carry the ball into some 40 yards. He rolled the ball to his right to Gusto, who returned the pass for Palmer to slam into the roof of the net.
Such a reliable penalty taker, and so it proves again. Sends Sanchez the wrong way, side foot into the bottom-right corner.
This looked a penalty in real time but the way it was given was bizarre. Initially the referee said play on after Kane tangled with Caicedo but a few seconds later he turned around and pointed to the spot. Can only assume it was the linesman's decision. It was one of those... clever bits of play from Kane. Caicedo was nowhere near the ball, but Kane made sure he tangled with the Chelsea player.
Chelsea guilty of giving the ball away at the edge of their box.
Bayern have not been especially convincing but they lead. Maresca was shaking his head and remonstrating with his coaching staff, they found themselves disorganised from the free-kick. The danger is that Bayern have the individual quality to take the game away from you.
From that retaken free-kick, Bayern played it short and worked the ball wide to the right. Chelsea switched off, but they may feel hard done by on the original call to give the foul.
Olise found himself up against Joao Pedro on the corner of the box, and worked a yard to cross with the shake of the ships. The low ball zipped across the six-yard box and hit the unfortunate Chalobah on the shin. He had to go for it with Upamecano who could have had a tap-in.
Better move from Bayern after Gnarby found himself the wrong side of Caicedo. Nice dummy from Kane, another feint from Gnabry, but his shot from 25 yards is blocked. Then Bayern win a free-kick to sustain the attack. Kimmich to clip the straight free-kick... and it hits the referee. Retake.
There continue to be boos and whistles every time Cucurella gets the ball from the Bayern fans. Now the home support are unhappy that Tah has been penalised for catching Joao Pedro in a sliding challenge. Not sure he has just cause for complaint.
Bayern have a free-kick in a crossing position after a very harsh call for handball. Taken short, Olise floats a cross to the back post but Chelsea had pushed up to the edge of the 18-yard box to play everyone offside.
Joao Pedro's movement and positioning is asking questions of the Bayern centre-backs. Chelsea finding it quite easy to find their attacking players in space. This time, Palmer picks out Gusto with a lovely pass and Upamecano hacks the cross behind for a corner. Taken short, Caicedo stands up a cross for Cucurella but he heads wide.
Neuer picks out Stanisic with a diagonal pass with Gusto forward. From there, Luis Diaz cut inside and fired a shot well over the bar from long range. Chelsea will be happy to see Bayern players trying their luck from there.
Likewise Serge Gnarby, who has another aimless shot from distance.
Another dangerous Chelsea attack stems from their right flank. This time it was Palmer who found space to drive towards the box in a one-on-one, and he played a clever pass towards the penalty spot but Pedro could not quite gather into his path. At the other end, a harmless Kane header from a long way out loops over the bar.
Quite a confident start from Chelsea, and encouragingly Sanchez has looked assured with the ball at his feet. When Bayern have had the ball, it has been among their defensive players and in front of Chelsea.
The Bayern fans clearly have long memories as they are loudly booing every touch of Chelsea left-back Marc Cucurella. It was Cucurella who got away with blocking the ball with his hand in the penalty area during Spain's European Championship quarter-final success over Germany last summer.
As expected, it is the same set-up as the Club World Cup final for Chelsea; James is playing in central midfielder next to Caicedo with Enzo Fernandez advanced and Palmer on the right. A big night for Tosin and Chalobah at the back.
And straight away Chelsea create an opening! Malo Gusto was high and wide on the right, and Robert Sanchez picked him out with a long pass forward. Gusto delivered into the box, and Pedro Neto almost met it on the bounce.
Chelsea's players then wanted a penalty for handball but nothing doing. Bright start.
The referee was having quite an earnest word with Maresca and Kompany before the game. Bayern get the game started.
Chelsea are two-time Champions League winners with several semi-final appearances to their name also. But under new ownership and with a new format, they almost feel like a new face. This is the first taste of Champions League football for most of their starting XI.
Bayern have just played their club anthem ahead of kick-off. A lot of it goes "la, la, la" but for anybody who couldn't quite grasp it, they kindly put the lyrics on the big screens. There is an "oh, oh, oh" section too.
Chelsea's co-controlling owners Behdad Eghbali and Todd Boehly are both inside the Allianz Arena for the club's return to the Champions League. It was in this stadium back in 2012, in the Roman Abramovich era, that Chelsea first won the competition, beating Bayern on penalties.
Cole Palmer makes his 100th appearance for Chelsea tonight. What a place for him to bring up his century.
Maresca has channelled the spirit of the Club World Cup success in his Chelsea line-up by playing captain Reece James in midfield and starting Malo Gusto behind Cole Palmer on the right.
The tactic worked spectacularly well against Paris St-Germain in the final, with Palmer scoring twice and assisting for Joao Pedro, who is starting up front in Munich.
Chelsea's chief operating officer Jason Gannon received an award on behalf of the club from Uefa, in honour of being the first team to win the Champions League, Cup Winners' Cup, Europa League, and Conference League.
Nicolas Jackson is in reserve for Bayern Munich and after signing from Chelsea on loan with an obligation to buy, he is available to play against his parent club. Alejandro Garnacho is also among the Chelsea substitutes.
Maresca's selection is an interesting one. Is Reece James playing as the right centre-back in a back three or is he playing alongside Caicedo in midfield with Palmer floating from the right? The main thing for Chelsea fans is seeing Palmer's name back on the team sheet. It is a very youthful Chelsea bench featuring Estêvão, Acheampong, George, Gittens and Buonanotte.
If James is in midfield with Palmer from the right, it is a reprise of the set-up Maresca used in the Club World Cup final against PSG.
Bayern unchanged from the weekend's win over Hamburg. They attack with something akin to a front four diamond: Olise right, Diaz left, Gnabry central with Kane at the tip.
Laimer is a central midfielder by trade filling in at right-back. Josip Stanisic has been getting a run at left-back.
Jose Mourinho is close to returning to Benfica after being sacked by Fenerbahce. Sam Wallace writes that Mourinho has been looking for a club who can adequately support him, and he may have just found that.
The shorts were on at this juncture. No sign of the (surely apocryphal) shin pads.
The Allianz Arena will always have a special place in the hearts of Chelsea supporters and tonight they return to the scene of their 2012 Champions League triumph to kick-off this year's campaign against Bayern Munich.
It is a fixture which should haunt Bayern fans, reminding them how they squandered so much dominance on home territory to allow Roberto Di Matteo's Chelsea to pinch the European Cup from under their noses. Didier Drogba more than played his part too, it should be said.
Now Chelsea are back in Europe's premier club competition for the first time since 2022-23. Enzo Maresca's team have the quality to trouble any team in the competition, but it is doubtful whether they have the maturity and defensive stability to go really deep. Chelsea's modern history shows they are capable of winning silverware without necessarily being at their best though, so they are a danger.
Compared to London rivals Arsenal and Tottenham, they appear to have a more stringent eight-game league phase though, with Bayern and Barcelona their pot one opponents and trips to Atalanta and Napoli on the horizon. Chelsea also faced Napoli in their 2012 run, and the same goes for Benfica who they host at Stamford Bridge in a fortnight. The Portuguese club may well be managed by Jose Mourinho should that appointment go through.
It has been an impressive start domestically for Bayern, with maximum points from three Bundesliga games and 14 goals scored in the process. There is a Premier League flavour to their attack with Luis Diaz joining Harry Kane and Michael Olise in their front three in a move from Liverpool in the summer. Bayern regained the league title last season, Kane's first major trophy of his career, but were knocked out of the Champions League by Inter Milan at the quarter-final stage. Vincent Kompany will likely be judged on European progress.
Chelsea have eight points from a soft first four Premier League fixtures and, aside from scoring five against a West Ham in disarray, are struggling to impose themselves on games. Perhaps they have tapered their training to avoid post-Club World Cup burnout.
Full team news on the way shortly.