Barcelona began their Champions League title defence with a two all draw with seven-times winners AC Milan at the Camp Nou on Tuesday night.
Alexandre Pato stunned the home side scoring after just 24 seconds. Barca replied 35 minutes later when Pedro slotted home a Lionel Messi pas across the face of goal.
David Villa put the hosts ahead five minutes after the restart with a delightful freekick, but as Barca thought they had done enough for the three points Thiago Silva ruined the day with a stoppage time equaliser.
Meanwhile BATE Borisov denied Viktoria Plzen victory in their first ever Champions League group stage game when a second-half goal from Renan Bressan secured a 1-1 draw in the other Group H fixture.
David Luiz and Juan Mata handed a youthful-looking Chelsea team and their new coach Andres Villas-Boas a winning start to their Group E campaign.
Fernando Torres setting up both goals to help beat Bayer Leverkusen in a hard-fought contest at Stamford Bridge.
Also in Group E Belgian champions Racing Genk held on for a goalless draw at home with the Spaniards of Valencia.
Borussia Dortmund’s Ivan Perisic scored with two minutes remaining to salvage a deserved one all draw with Arsenal in their Group F opener while Marseille put their domestic troubles aside to claim 1-0 win over Olympiakos.
Brazilians Hulk and Kleber hit the mark to hand Europa league champions Porto a 2-1 win over a nine-man Shakhtar Donetsk in Group G as APOEL Nicosia stunned Russian heavyweights Zenit St. Petersburg.