London, Sep 14 (IANS): Defending champions Barcelona were stunned by a goal by A.C. Milan within seconds of kick-off and another in stoppage time of their opening Group H Champions League game which ended in a 2-2 draw Tuesday.
Struggling English Premier club Arsenal, too, were surprised by a late goal in their 1-1 split verdict against Borussia Dortmund in Group F while another English side Chelsea won their match against Bayer Leverkusen 2-0 in Group E.
Alexandre Pato scored the first Milan goal and as Pedro Rodriguez and David Villa struck a goal each Barcelona looked in control of the game till a Thiago Silva header gave Milan a point.
Robin van Persie's first-half goal for Arsenal looked secure till a Ivan Perisic volley tied the score.
Chelsea's new manager Andre Villas-Boas saw his side win comfortably, his former club Porto rallied to beat nine-man Shaktar Donetsk 2-1 in Group G.
Barcelona have won the Champions League twice in three years, while Porto took the Europa League honours last season.
Barcelona is seen as world soccer's superpower and coach Pep Guardiola's boys are favourites to win Europe's premier club championship for the fifth time.
Injured Zlatan Ibroahimovic and Robinho were missing from the Milan line-up and yet the Italian side fought it out to share points at the Nou Camp. A goal in only 24 seconds as Pato coolly slipped the ball past goalkeeper Victor Valdes put them on top.
Lionel Messi provided the opening for the Spanish champions to tie the score, Pedro Rodriguez scoring in the 36th minute.
Five minutes into the second half, Villa's long-range free kick curled into the net put Barcelona ahead.
Milan coach Massimiliano Allegri said his side could have played better after the lead. "I am happy the team did not collapse until we found the late equaliser," he said.
The equaliser came when Thiago jumped high to meet Clarence Seedorf's corner.
"In the Champions League, teams can create goals out of nothing against you and you can end up with egg on your face as was the case tonight," UEFA website quoted Barcelona winger Daniel Alves as saying.
"We played a great game but we didn't kill it off and we saw the consequences against a great rival," he added.
All four teams in Group H are on one point after BATE Borisov and Viktoria Plzen tied 1-1.
In Germany, Arsenal went ahead just before halftime when Van Persie seized the ball from Sebastian Kehl and after a one-two with Theo Walcott shot past Dortmund goalkeeper Roman Weidenfeller.
In the closing minutes, Marcel Schmelzer's free kick was only partially cleared by Kieran Gibbs and Ivan Perisic charged in to volley home the equaliser.
The draw enabled Marseille to go to the top of the group with Lucho Gonzalez's lone goal against Olympiakos.
The Argentine cashed in on a chink in the Greek defence to reach Jeremy Morel's cross and beat his former River Plate teammate Franco Costanzo in the Olympiakos goal.
At Stamford Bridge, Fernando Torres is still searching for a goal, but he set up both the Chelsea goals.
David Luiz latched onto Torres' layoff before beauty found the bottom corner of the net midway through the second session.
Then Torres ran down the left flank and all Juan Mata had to do was to give his effort a finishing touch and with it the game ended.
Chelsea are at the top of Group E after Racing Genk drew 0-0 with Valencia in the other group match.
In Group G both games resulted in 2-1 victories.
Porto goalkeeper Helton gifted Shakhtar the lead in the 12th minute as he could not collect a weak shot from outside the area by Williams and as he dropped the ball, Luiz Adriano was there to tap it in.
By the 30th minute, Hulk equalised for Porto from a free kick, and James Rodriguez's cross saw Kleber slot home the winner six minutes after halftime.
For APOEL Nicosia it was a first-ever Champions League victory. Second-half goals from Gustavo Manduca and Ailton gave them a 2-1 win over Zenit St.Petersburg.