Barcelona’s Deco (left) and Ronaldinho celebrate a goal against Werder Bremen at Nou Camp on Tuesday. (Reuters)

Former European champions Juventus, Bayern Munich and Ajax Amsterdam all qualified for the last 16 of the Champions League on Tuesday but Manchester United stumbled again and are not sure of their place yet.

Seven of the last 16 are now known with Arsenal, Barcelona, Olympique Lyon and Real Madrid all through.

United, however, in their first European game since the departure of captain Roy Keane after 12 years and nearly 500 games, failed to score in the Champions League for the seventh time in eight matches as they drew 0-0 at home to Villarreal.

Their place in the last 16 now hangs in balance, but their cause was helped when Lille drew 0-0 with Benfica, which was disappointing for a 76,079 crowd at the Stade de France in Paris ? a record to watch a French team in European competition.

Bayern Munich crushed Rapid Vienna 4-0 at home with Dutchman Roy Makaay scoring twice to ensure they would finish either first or second in Group A along with Juventus.

The Italian champions beat Club Bruges 1-0 at home with a late goal from Alessandro Del Piero to make sure of their place in the last 16 but, in stark contrast to Paris, just 9,623 fans turned up at the Delle Alpi to watch the game.

Despite the defeat, Bruges will finish third in the group and go into the Uefa Cup while Rapid, who have lost all five matches to date, are eliminated from Europe.

Arsenal had already qualified from Group B before Tuesday’s win over Thun but clinched top spot after beating the Swiss outsiders 1-0 with a late Robert Pires penalty which meant they had scored in each of their last 21 Champions League matches.

Ajax, playing their 150th match in Europe’s premier club competition, celebrated by making sure they would advance with Arsenal after a 2-1 home win over Sparta Prague, who have now played 13 Champions League matches since their last win.

Sparta skipper Martin Petras pulled one back for his side in the final minute but Ajax held on for the points.

Barcelona, who had already qualified, made sure they would advance as winners of Group C with a 3-1 win over Werder Bremen, highlighted by another outstanding display from Ronaldinho. The Brazilian made a goal apiece for Gabri and Henrik Larsson ? and also scored one.

Bremen’s miserable night was completed when Miroslav Klose, the top scorer in the Bundesliga with 14 goals this season, went off with a broken bone in his face after a challenge with Rafael Marquez and now faces surgery and three weeks out injured.

Despite the defeat, though, Werder are still in with a chance of qualifying although Udinese have a better one.

The Italians came from behind to win 2-1 at Panathinaikos, moving up from bottom of the section to second on seven points. (REUTERS)