* Ribery nets twice and sets up two more goals for leaders
* Leverkusen tighten grip on second with 1-0 win at Dortmund
* Ten-man Schalke beaten 2-1 at fourth-placed Gladbach (updates with Dortmund result)
BERLIN, Dec 7 (Reuters) - Bayern Munich humiliated former Bundesliga powerhouses Werder Bremen 7-0 on Saturday with Franck Ribery scoring twice and setting up another two as the champions kept up their seemingly unstoppable march towards another title.
It was the first time in over half a century that Bayern had struck seven times at Bremen's Weser stadium, once a fortress when the sides battled for league domination until a decade ago.
Frenchman Ribery was in top form after returning from a rib injury and lifted the Bavarians to 41 points from 15 games with their 40th consecutive league match without defeat.
They also equalled a club record with their 26th straight away game without a loss.
Bayer Leverkusen tightened their hold on second place, moving to 37 points with a 1-0 victory at Borussia Dortmund, who are stuck in third on 31, level with Borussia Moenchengladbach who won 2-1 at 10-man Schalke.
"I have to say a big thank you to my players because they had an exceptional game," said Bayern's Pep Guardiola, who set a record as the first new Bundesliga manager to be undefeated in his opening 15 league games.
"It was an honour to be coach here today. As for Franck he repeatedly showed us what kind of class he possesses."
Assani Lukimya scored Bremen's 50th Bundesliga own goal to put Bayern in front after 21 minutes following a cutback in the box from Ribery.
Defender Daniel van Buyten rose above everyone to head in the second goal six minutes later before Ribery's chip put the game beyond doubt in the 38th minute.
After missing several chances Bayern's Croatia striker Mario Mandzukic finally struck from close range following a Ribery assist on the hour.
Thomas Mueller then drilled the ball home from 16 metres before Ribery and Mario Goetze completed a rout that will heap the pressure on Werder coach Robin Dutt.
Dutt's team, who have won once in their last nine league games, are fifth from bottom.
Dortmund lacked their usual sharpness and were left chasing visitors Leverkusen after Son Heung-min's early first half goal.
It was Dortmund's third defeat in their last four league games and both teams finished with 10 men after Leverkusen's Emir Spahic was sent off for hitting out at an opponent with 10 minutes let and the home side's Sokratis Papastathopoulos was booked for a second time in stoppage time.
Schalke 04 coach Jens Keller is also under pressure after they slumped to defeat at Moenchengladbach, who notched their sixth straight win to go seven points clear in fourth place.
Schalke's misery was sealed on the stroke of halftime when captain Benedikt Hoewedes was sent off with a second booking for handball and Max Kruse converted the resulting spot kick for Gladbach's seventh straight home win.
Keller's future at the club could depend on next week's crunch Champions League match against FC Basel for a spot in the knockout stage.
Hamburg SV were beaten 1-0 by visitors Augsburg to drop to 13th, level on points with northern rivals Werder. (Reporting by Karolos Grohmann; editing by Pritha Sarkar and Ken Ferris)