Pato struck for AC Milan inside 25 seconds at Camp Nou, the fifth fastest in Champions League history and the earliest on any matchday one. Pedro Rodríguez and David Villa scored either side of half-time to give Barcelona the advantage but the reigning champions were denied at the death by Thiago Silva. In the other Group H game, Marek Bakoš claimed Viktoria Plzen’s first goal in the Champions League just before half-time against BATE Borisov, who came back to draw 1-1 in Prague.
Borussia Dortmund needed a late goal Ivan Perišić to draw with Arsenal in Germany. Robin Van Persie had given the Gunners the lead, but Perisic’s brilliant volley two minutes from time ensured that the points were shared. Elsewhere in Group F, Marseille held on to beat Olympiacos 1-0.
Europa League holders Porto defeated nine-man FShakhtar Donetsk 2-1 while in the other Group G game APOEL came from behind to defeat Zenit St Petersburg by the same scoreline,
Chelsea FC 2-0 Bayer 04 Leverkusen
KRC Genk 0-0 Valencia CF
Olympiacos FC 0-1 Olympique de Marseille
Borussia Dortmund 1-1 Arsenal FC
FC Porto 2-1 FC Shakhtar Donetsk
APOEL FC 2-1 FC Zenit St Petersburg
FC Barcelona 2-2 AC Milan
FK Viktoria Plzeň 1-1 FC BATE Borisov