Bayern boss Jupp Heynckes celebrated his 1000th Bundesliga game as a player or coach by making six changes from the team which won 3-1 at Arsenal in the Champions League on Tuesday.

But they still extended their unbeaten run to 20 matches since their last defeat at home to Bayer Leverkusen at the end of October while resting their top players for Wednesday's German Cup quarter-final at home to Dortmund.

"After making those six changes, we needed 20 minutes to find our rhythm," said Heynckes, with only ex-Greece coach Otto Rehhagel having been involved in more Bundesliga matches with 1,037.

"We saw some nice goals out there, but we didn't reckon with conceding one, that was annoying," added Heynckes, whose team last conceded a league goal on December 14 in a 1-1 draw against Moenchengladbach.

"Those players who came in justified my confidence in them. The game on Wednesday will be a real cup battle."

Amongst the key changes, Germany striker Mario Gomez, who scored twice, came in for Mario Mandzukic, Dutch wing Arjen Robben, who opened the scoring, started for Thomas Mueller while Swiss midfielder Xherdan Shaqiri took Toni Kroos' place.

The other goals came from France wing Franck Ribery and Spain defensive midfielder Javi Martinez, while Bremen's Theodor Gebre Selassie turned the ball into his own net early in the second half.

Bremen were reduced to 10 men when centre-back Sebastian Proedl was shown a straight red card for bringing down Gomez, who was through on goal, just before the break.

Belgium midfielder Kevin de Bruyne, on loan at Bremen from Chelsea, pulled a goal back for Werder approaching the hour mark, but Bremen's defence capitulated by leaking two goals in the final five minutes.

The two teams closest to Bayern, Borussia Dortmund, who are at Moenchengladbach, and Bayer Leverkusen, at bottom side Greuther Fuerth, need to pick up wins on Sunday to cut Bayern's huge lead.

Later, Schalke 04 built on Wednesday's 1-1 Champions League draw at Galatasaray with a 2-1 victory at home to strugglers Fortuna Duesseldorf, only the Royal Blues' second league win since mid November.

Cameroon defender Joel Matip scored both Schalke's goals, including the 81st minute-winner after being set up by Brazil midfielder Michel Bastos.

"It wasn't pretty, but in our situation, all that counts is the three points, although we have to ask ourselves why Fortuna were able to come back," said Matip, whose side stay ninth.

South Korean striker Ji Dong-Won scored his first goal in six appearances for strugglers Augsburg since joining from Sunderland in January in his team's 2-1 win at home to Hoffenheim.

It was only Augsburg's third win of the season and they move up to 16th in the league, nine points from safety, while Hoffenheim drop to 17th and deeper in the relegation mire.

Hanover bounced back from their midweek Europa League exit at the hands of Russia's Anzhi Makhachkala with a 5-1 win over guests Hamburg to move up to seventh.

Ivory Coast's Didier Ya Konan, playing on the right wing, scored twice including a superb volley from 20 metres out just before the break.

Wolfsburg earned a 1-1 draw at Mainz 05 despite playing with 10 men for 60 minutes after centre-back Alexander Madlung was shown an early red card for pulling back Mainz's Nicolai Muelle.

Nuremberg earned a 1-1 draw at Stuttgart to stay 14th and just above the relegation place.