Holders Bayern Munich survived an early battering to beat 10-man Arsenal 2-0 on a night of drama in the Champions League on Wednesday as both teams missed penalties and home goalkeeper Wojciech Szczesny was sent off.
A year to the day after the Germans beat Arsenal 3-1 at the Emirates Stadium in their last-16 first leg tie, second-half goals from the outstanding Toni Kroos, who curled in a right-foot shot, and substitute Thomas Mueller put the champions a giant step closer to the quarter-finals.
Earlier, Arsenal's German midfielder Mesut Ozil missed an eighth-minute penalty and David Alaba did the same for Bayern 32 minutes later after Szczesny was dismissed by Italian referee Nicola Rizzoli for clattering Arjen Robben in the area.
The referee made a decision that basically killed the game...It isn't over because we will fight until the end. Last year we lost here and won there and we have to try and do that again.
Arsenal now have to better what they did a year ago in the second leg when they almost defied the odds by coming back to win 2-0 in Munich as Bayern advanced on the away goals rule.
The Bavarians returned to London in May to beat Borussia Dortmund in an all-German final at Wembley and Wednesday's game was their first match back in the capital since.
Bayern's victory came 24 hours after Barcelona inflicted a 2-0 home defeat on Manchester City, making it unlikely that two of England's dominant clubs will advance much further this season.
Arsenal, like City on Tuesday, ended the match with 10 men but unlike their Premier League rivals they took the game to their opponents and, certainly until Szczesny's sending-off, gave as good as they got.
"The referee made a decision that basically killed the game," manager Arsene Wenger told reporters, echoing the sentiments of City boss Manuel Pellegrini the night before.
"I think our keeper went in for the ball, he touched Robben who made more of it (than he should) and I told Robben that.
"It isn't over because we will fight until the end. Last year we lost here and won there and we have to try and do that again."
Pep Guardiola, who took over from Jupp Heynckes as Bayern coach in the close season, said: "We were lucky. Our keeper Manuel Neuer, the best in the world, showed his qualities.
"After that we played better and started dominating the game and in the end we deserved to win it."
In the night's other match Atletico Madrid gave AC Milan coach Clarence Seedorf an unhappy return to a competition he graced so magnificently as a player when the Spaniards first frustrated their opponents before snatching a late 1-0 win.
Diego Costa scored the only goal at the San Siro with a magnificent header seven minutes from time as Atletico proved too cagey and wily for Milan, who twice hit the woodwork in the first 20 minutes.
Atletico, with coach Diego Simeone prowling the touchline in his familiar all-black outfit, tweaked Milan's nerves with repeated tactical fouling in midfield, giving away 20 free kicks
"We are a normal team and we try to profit from the situations we create," former Argentina captain Simeone told reporters.
"We work with humility, we started gaining metres and we felt better as the game went on."