Injury-time goals for Arsenal [Images] and Ajax Amsterdam provided a dramatic start to Group B of the Champions League on Wednesday as the Londoners beat Swiss outsiders Thun 2-1 and Ajax grabbed a 1-1 draw at Sparta Prague.

Benfica also struck in stoppage time to beat Lille 1-0 in Lisbon and take the early lead in Group D after Manchester United [Images] drew 0-0 at Champions League debutants Villarreal.

Udinese, also in the competition for the first time, got off to a flying start as they thumped Panathinaikos 3-0 with a hat-trick by Italy [Images] international Vincenzo Iaquinta.

Juventus won 2-1 at Club Bruges to make it a clean sweep of victories for the four Italian clubs after AC Milan and Inter Milan won on Tuesday.

Udinese are joined on three points in Group C by Barcelona, 2-0 winners at Werder Bremen, while Bayern Munich won 1-0 at Rapid Vienna to share the early lead in Group A with Juventus.

ARSENAL DISMISSAL

Thun were playing in the amateur Swiss third division nine years ago but showed they had come a long way by beating Dynamo Kiev and Malmo in the Champions League qualifying rounds.

The trip to Arsenal demanded a further step up and they responded to the challenge to reach halftime goalless, with the London [Images] side reduced to 10 men just before the break with a red card shown to striker Robin van Persie for dangerous play.

Arsenal's Brazilian midfielder Gilberto Silva headed the opening goal after 51 minutes but Highbury was stunned when Nelson Ferreira looped in an equaliser two minutes later.

Arsenal struggled to find further openings until 36-year-old substitute Dennis Bergkamp slotted home the winner with his first Champions League goal for three years.

Sparta also looked on course for something of an upset after Miroslav Matusovic slammed in a superb volley after 66 minutes.

However, Ajax grabbed a point with another shot from outside the box by Wesley Sneijder [Images].

WOEFUL START

Benfica, suffering a woeful start to their domestic campaign, left it late to give their fans something to cheer at last as striker Fabrizio Miccoli headed past the previously dominant Lille keeper Tony Sylva.

Villarreal almost matched them as Marcos Senna hit the bar in the last minute against a Manchester United side who had England [Images] striker Wayne Rooney [Images] sent off midway through the second half for ironically clapping the referee, who had just booked him for a foul.

Juventus also saw red as Patrick Vieira was dismissed in the 89th minute in Bruges -- but only after Pavel Nedved and David Trezeguet had secured their victory.

Udinese, fourth in Serie A last season, were far too good for competition regulars Panathinaikos. Iaquinta struck after 28, 73 and 76 minutes to complete a great week for the Italian sides.

On Tuesday AC Milan beat Fenerbahce 3-1 and Inter won 1-0 at Slovak side Artmedia Bratislava.

BAYERN FLATTERED

Bayern Munich were somewhat flattered by their 1-0 win in Vienna. Peruvian striker Paolo Guerrero got the only goal after an hour but Rapid blew their chance to equalise when Jozef Valachovic sent a penalty wide eight minutes from time.

Barcelona were also lucky to come away from Germany [Images] with three points after Werder Bremen missed a host of chances.

The Spanish champions went ahead with a scruffy Deco goal after 13 minutes and somehow won it with a second-half Ronaldinho [Images] penalty.

The group stage started with a bang on Tuesday as nine-time champions Real Madrid [Images] were thumped 3-0 by Olympique Lyon.

Holders Liverpool, having come through three qualifying rounds, won 2-1 at Real Betis and there were wins for last year's losing semi-finalists Chelsea and PSV Eindhoven as well as Rosenborg Trondheim and Rangers.

The action resumes in two weeks when the games include Ajax v Arsenal, Barcelona v Udinese, Liverpool v Chelsea and Manchester United v Benfica.

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