Arsenal and Chelsea kicked off with wins, Sevilla made an explosive start and AC Milan scraped a victory in Luxembourg.
Group A: Ludogorets 2-3 Leverkusen, AEK Larnaca 0-1 Zürich
Group B: Celtic 1-0 Rosenborg, Leipzig 2-3 Salzburg
Group C: Slavia Praha 1-0 Bordeaux, København 1-1 Zenit
Group D: Dinamo Zagreb 4-1 Fenerbahçe, Spartak Trnava 1-0 Anderlecht
Group E: Arsenal 4-2 Vorskla, Sporting CP 2-0 Qarabağ
Group F: Olympiacos 0-0 Betis, Dudelange 0-1 Milan
Group G: Rapid Wien 2-0 Spartak Moskva, Villarreal 2-2 Rangers
Group H: Lazio 2-1 Apollon, Marseille 1-2 Frankfurt
Group I: Genk 2-0 Malmö, Beşiktaş 3-1 Sarpsborg
Group J: Akhisar 0-1 Krasnodar, Sevilla 5-1 Standard Liège
Group K: Dynamo Kyiv 2-2 Astana, Rennes 2-1 Jablonec
Group L: Vidi 0-2 BATE, PAOK 0-1 Chelsea
