Liverpool twice squandered the lead, trailed 3-2 and then scored three times in the last 25 minutes to win 5-3 at Young Boys in an enthralling but blunder-prone Europa League tie on Thursday.
Chile forward Eduardo Vargas scored a hat-trick to propel Napoli to a 4-0 win over AIK Stockholm and titleholders Atletico Madrid won 3-0 at Hapoel Tel Aviv as the monstrous group phase got under way.
Liverpool, effectively fielding a reserve team in Berne, were gifted a fourth minute lead with a bizarre own goal as Christoph Spycher headed the ball straight at teammate Juhani Ojala and it ricocheted into the net.
Liverpool returned the gift when Jose Enrique lost the ball in the penalty area and Raphael Nuzzolo fired into the roof of the net in the 38th minute, only for Andre Wisdom to head Liverpool back in front almost immediately.
Ojala equalised and Gonzalo Zarate put the Swiss ahead with a delightful dinked finish. Then Uruguay defender Sebastian Coates made it 3-3 after another Young Boys mix-up and two goals from Jonjo Shelvey won the game for the three-times UEFA Cup winners.
Cristian Rodriguez and Diego Costa scored twice in three minutes before halftime for Atletico in Group B and Raul Garcia completed the scoring.
There were dramatic finishes at Fenerbahce, where visitors Olympique Marseille scored twice in the last 10 minutes to force a 2-2 draw, and AEL Limassol where Borussia Moenchengladbach missed a penalty in the eighth minute of stoppage time in a 0-0 draw.
Caner Erkin and Alex put Fenerbahce 2-0 ahead inside the hour before Andre Ayew inspired Marseille's revival, setting up one goal for Mathieu Valbuena in the 83rd minute and scoring the equaliser in stoppage time.
Gladbach, who like Liverpool left several regular players out of the team, should still have won their game in Cyprus but Oscar Wendt fired his penalty against the crossbar.
Udinese also provided some late drama as talismanic striker Antonio Di Natale scored an injury time equaliser to give them a 1-1 draw at home to big-spending Russians Anzhi Makhachkala.
Photograph: Pascal Lauener/Reuters
