LONDON, Dec 5 - Barcelona celebrated their 400th European match by beating Werder Bremen 2-0 to reach the knockout phase of the Champions League on Tuesday, with AS Roma also earning a last 16 berth with a 1-0 victory over Valencia.

Chelsea secured top spot, above Barcelona, in Group A with a 2-0 home win over Levski Sofia while the top two in Group D drew 1-1 in Munich, leaving Bayern first and Inter Milan second.

Barcelona needed to win to avoid the ignominy of becoming the first holders to go out before the knockout stage and started full of running and attacking intent.

The clash between the league leaders of Spain and Germany at the Nou Camp was effectively sealed in the first 20 minutes when the hosts went 2-0 up.

Ronaldinho opened the scoring in the 13th minute, cleverly drilling a free kick under the leaping Bremen wall and beyond keeper Tim Wiese, and Eidur Gudjohnsen got the second in the 19th when he tucked away a Ludovic Giuly cross.

The Iceland striker then hit a post after a brilliant slalom through the Werder defence, Giuly missing an open goal from the rebound.

The Germans eventually settled to exert some pressure, knowing a draw would be enough to send them through in Barca's place, but though they dominated the second half Werder failed to create many clear chances.

CRUISE CONTROL

Chelsea, already assured of progress, were on cruise control against Levski once Andriy Shevchenko got his first European goal for the club in the 27th minute.

Substitute Shaun-Wright Phillips drove home the second seven minutes from the end.

Roma, needing only a draw, reached the knockout phase for the first time thanks to Christian Panucci's header after 13 minutes.

The result meant Roma finished second behind Valencia and ahead of Shakhtar Donetsk, who drew 1-1 with Olympiakos to grab a UEFA Cup slot.

Bayern secured first place in Group B despite conceding a late equaliser.

Striker Roy Makaay blasted Bayern ahead in the 62nd minute but Inter, fielding a weakened team, grabbed an equaliser through Patrick Vieira.

The other Group B game was notable for Spartak Moscow ending a Champions League record run of 22 games without a win as they beat Sporting 3-1 in Lisbon to snatch third place and a UEFA Cup spot.

With everything already settled in Group C, leaders Liverpool will not lose too much sleep over their 3-2 defeat at Galatasaray, who finished bottom.

Runners-up PSV Eindhoven were also off the pace as they went down 3-1 at home to Girondins Bordeaux.

The final four qualification places up for grabs will be settled on Wednesday.