Manchester United staged a late fightback but it wasn't enough as Bayern Munich claimed a 4-3 win in their Champions League group-stage opener on Wednesday.
Harry Kane scored a second-half penalty as Bayern handed United a fourth defeat in just six matches in all competitions.
Goals from Leroy Sane and Serge Gnabry in the 28th and 32nd minutes put the hosts firmly in the driving seat with injury-hit United, who have now lost their last three matches, pulling a goal back in the 49th through Rasmus Hojlund's deflected effort.
Bayern ended United's hopes of a comeback four minutes later with a Kane penalty, awarded for a handball by Christian Eriksen, to restore their two-goal cushion.
Casemiro slotted in from close range in the 88th minute but substitute Mathys Tel scored once more for Bayern in stoppage time. Casemiro headed in another for United with the last move of the game.
“We lost a bit of concentration there in the last five minutes,” Kane, who has now scored five goals in as many starts for Bayern since joining from Tottenham, told TNT Sports.
“Thankfully we were able to hold on to the lead. It's always great to score. Always room for improvement.
“Really good night tonight, we've started the season well and we can improve in certain areas but I feel like we are building towards that.”
The match started on a different note as United controlled possession and forced Bayern on to the back foot.
Andy Mitten reports from Munich on Manchester United's Champions League loss
Bayern would strike first, however, thanks to some clever work from Kane and Sane – and a poor mistake from Andre Onana.
Sane evaded his marker and threaded a ball to Kane, who guided the ball back into the path of the former Manchester City winger. Sane slid the ball goalwards and Onana made a meal of the save and allowed it to trickle into the net.
Bayern celebrated as Onana lay forlorn on the Allianz Arena turf.
Bayern's second came about mainly thanks to the individual brilliance of Jamal Musiala. The midfielder collected the ball near the halfway line and dribbled goalwards, fending off the attention of several United defenders before squaring for Gnabry.
The former Arsenal forward slammed the ball into the net to leave United 2-0 down.
The visitors fought back just after half-time. Following a poor back-pass from Musiala, Marcus Rashford found summer signing Hojlund whose deflected shot evaded goalkeeper Sven Ulreich.
United's hope was short-lived however with a VAR review finding a handball in the box from Eriksen.
United complained about the call, with Eriksen clearly trying to withdraw his arm while having little time to react, but Kane stepped up and converted the spot-kick, his fifth goal in five starts for Bayern.
United rallied late on, Casemiro scoring either side of a Tel goal, but Bayern were never in serious danger of relinquishing the three points.
United, who lost 3-1 to both Brighton & Hove Albion and Arsenal in their previous two games, have now conceded three goals or more in three consecutive matches for the first time since December 1978.
