Arsenal turned the form book upside down and gave manager Arsene Wenger much-needed respite with a shock 2-0 win away to AC Milan in the Europa League on Thursday.
Lazio completed an unhappy night for Italian clubs when they were held 2-2 at home by Dynamo Kiev while Bundesliga side Borussia Dortmund suffered a shock 2-1 home defeat by Austrian champions Salzburg.
Twice former champions Atletico Madrid eased past Lokomotiv Moscow 3-0 as all three Russian clubs lost.
Arsenal, who had lost their last four games in all competitions and were facing a Milan team unbeaten in 13 matches, stunned the San Siro with first-half goals from Henrikh Mkhitaryan and Aaron Ramsey in the round of 16 first leg.
Arsenal were on the ropes in recent weeks, as Wenger admitted afterwards.
“It’s like a boxing match,” he said. “You are half knocked down and have to face another opponent before you get up again.”
For Milan, who had not conceded a goal in 539 minutes before Mkhitaryan’s effort, this was a night to rue their own sloppiness. A speculative shot from Suso that bobbled out for a throw-in seemed to encapsulate their night.
“We committed a lot of mistakes,” Milan coach Gennaro Gattuso said. “I probably made some mistakes in not making myself understood. We suffered.”
Wenger added: “We were not in a position to take risks, but we could not be too cautious as you lose fluidity. We defended with resilience until the end.”
Elsewhere, Valon Berisha scored twice early in the second half, the first from a penalty, as Salzburg stunned Dortmund, who replied through Andre Schuerrle.
Saul Niguez set Diego Simeone’s Atletico on their way against Lokomotiv Moscow with a rising 25-metre shot before Diego Costa and Koke struck to complete an easy win for the Spanish side in Madrid.
Olympique Lyonnais defied freezing conditions to win 1-0 at CSKA Moscow thanks to Marcelo’s second-half strike and RB Leipzig beat Zenit St Petersburg 2-1 after second-half goals from Bruma and Timo Werner.
However, Domenico Criscito brought Zenit right back into the tie when he scored from a free kick in the 86th minute.
There were four second-half goals in less than half an hour in Rome where Viktor Tsigankov gave Kiev the lead in the 52nd minute before Ciro Immobile, with his 33rd goal of the season, and Felipe Anderson turned the game around for the Serie A side.
However, Dynamo levelled in the 79th minute with a superb effort from Junior Moraes who collected the ball on the edge of the area, turned and curled his shot past Thomas Strakosha.
Lucas Ocampos scored twice, including the Europa League’s fastest goal of the season after 36 seconds, to set Olympique Marseille on the way to a 3-1 win over Athletic Bilbao.
Dimitri Payet netted Marseille’s other goal, his first in Europe since 2009 when he was on target for St Etienne, and 37-year-old forward Aritz Aduriz replied with a penalty for the visitors.
Fredy Montero scored twice either side of halftime to give Sporting, Portugal’s last European survivors, a 2-0 win at home to Viktoria Plzen in the other game.