Holders Liverpool, Chelsea and Olympique Lyon set a course for the Champions League knockout stage but there was a scare for Real Madrid on Wednesday.
Lyon, who opened their Group F campaign with a 3-0 drubbing of Real, look certain to qualify after reaching nine points from three games with a 2-1 win over Olympiakos Piraeus.
Real moved up to second place on six points but were trailing 1-0 to Norwegian outsiders Rosenborg Trondheim in the second half before running out 4-1 winners.
English defender Jonathan Woodgate, scorer of two own goals this season, got the equaliser, Raul extended his European Cup scoring record to 51 and further strikes from Ivan Helguera and David Beckham turned victory into a rout.
Premier League rivals Chelsea and Liverpool, on seven points apiece, are favourites to qualify in Group G after the English champions crushed Real Betis 4-0 at Stamford Bridge and the European champions edged Anderlecht 1-0 in Brussels.
Inter Milan's hopes of a third straight win were dashed by a 2-0 defeat away to 2004 champions Porto but they still lead Group H after Rangers only drew 0-0 at home to Artmedia Bratislava.
Last season's losing finalists AC Milan had to settle for a 0-0 draw with PSV Eindhoven in a re-run of their semi-final with the Dutch side earlier this year.
They still lead Group E after a six-goal thriller ended 3-3 between Fenerbahce and Schalke 04 in Turkey.
IMPRESSIVE CHELSEA
Big-spending Chelsea were the night's most convincing winners after a wobbly start, with Jose Mourinho's side ripping the Spaniards to shreds.
Ivory Coast striker Didier Drogba steered home the first, Portugal defender Ricardo Carvalho pounced on a goalkeeping blunder to make it 2-0 before the break and England's Joe Cole rifled in a superb third.
Though Argentine substitute Hernan Crespo headed the fourth, Chelsea's most impressive player was Ghanaian Michael Essien, utterly dominant in midfield.
France striker Djibril Cisse scored Liverpool's winner after 20 minutes, volleying home a Dietmar Hamann corner.
However, they faced plenty of second-half pressure before handing Anderlecht a record 10th consecutive Champions League defeat and joining Chelsea with a four-point lead over Betis.
Lyon looked to be cruising after Brazilian midfielder Juninho gave them an early lead with a trademark free kick, only for Pantelis Kafes to level in the 84th minute with a fine dipping shot.
There was still time, however, for Juninho to set up Sidney Govou for Lyon's winner from close range in the 89th minute.
England captain David Beckham was the architect of a Real victory which put their campaign for a 10th European Cup back on track.
Beckham, on sparkling club form this season, provided the crosses for both Woodgate, whose own goals came on his Real debut and then in a friendly, and also Helguera.
Beckham rounded off his performance in the 82nd minute by bending a superb free kick round the Rosenborg wall.
INTER BEATEN
Inter were out of luck in Portugal, where defender Marco Materazzi conceded an own goal after 22 minutes and Porto's South African striker Benni McCarthy made it 2-0 at the second attempt after his free kick was blocked.
Inter are two points clear of Rangers and Artmedia, whose match in Glasgow ended in boos from a disgruntled home crowd.
Inter's city rivals AC Milan completed a frustrating time for Italy's four clubs - none of which won this week after Juventus lost to Bayern Munich and Udinese drew with Werder Bremen.
Milan's draw left them with five points in a tight group.
Fenerbahce, whose Ghanaian midfielder Stephen Appiah struck a superb equaliser to earn them that 3-3 home draw, and PSV have four points each, while Schalke have two.
