BERLIN -- Arjen Robben scored a hat trick as Bayern Munich routed Schalke 5-1 on Saturday to extend its Bundesliga lead to 20 points, a league record after 23 games.
David Alaba opened the scoring with a deflected free kick in the third minute, Robben chipped in his first in the 15th, Mario Mandzukic's header made it 3-0 in the 24th, and Robben claimed his second in the 28th, with a fine finish inside the far post.
"It was embarrassing what we delivered in the first half," Schalke captain Benedikt Hoewedes said. "We had much too much respect."
It was utter dominance from Bayern in the first half, with more than three-quarters ball possession, 409 completed passes to Schalke's 65, and a successful pass rate of 91 per cent.
"The first half was the worst I have ever seen from us," Schalke coach Jens Keller said.
His side improved after the break, and pulled one back through former Schalke player Rafinha's own goal off a corner in the 64th.
Robben claimed his third from the penalty spot in the 77th, after Kyriakos Papadopoulos was sent off for conceding the foul on Mandzukic. TV replays showed it was a harsh decision.
"It was fun today," Robben said.
Schalke was beaten 6-1 at home by Real Madrid in the Champions League midweek, and sporting director Horst Heldt said, "Altogether it was a disastrous week."
Bayern stretched its league record unbeaten run to 48 games after its 15th win in a row -- also a league record.
Earlier, Borussia Dortmund took advantage of Bayer Leverkusen's freefall by beating Nuremberg 3-0 at home to move to second.
Leverkusen lost 1-0 at home to Mainz for its fifth consecutive defeat across all competitions, its eighth from 10 games. Eric Maxim Choupo-Moting scored with his heel in the 37th minute for Mainz, which was simply cleverer than the home side.
"There's a big concern that we'll miss all our targets," said Leverkusen sporting director Rudi Voeller, whose side faces an uphill challenge to overturn a 4-0 loss to Paris Saint-Germain in the Champions League and is already knocked out of the German Cup.
Second-half goals from Mats Hummels, Robert Lewandowski and Henrikh Mkhitaryan gave Dortmund a comfortable win after a difficult first half.
"We were often running around after them," Nuremberg striker Josip Drmic said. "They showed us how to do it and used their chances."
Werder Bremen beat Hamburger SV 1-0 in the league's 100th northern derby to leave its rival mired in the relegation playoff place.
Augsburg drew with Hannover 1-1 and Eintracht Braunschweig drew with Borussia Moenchengladbach by the same score.
Nuremberg 'keeper Raphael Schaefer made a host of saves to ensure a frustrating first half for Dortmund, and Tomas Pekhart hit the post for the visitors.
The home side got off the mark in the 51st when Schaefer saved Lewandowski's header from Nuri Sahin's free kick, and Hummels followed-up on the line.
TV replays showed Lewandowski was marginally offside. The Poland striker hit his league-leading 15th goal in the 64th, when Mkhitaryan played him through to pick his spot.
Mkhitaryan rounded off the scoring with seven minutes remaining to round off a successful week for Dortmund, which beat Zenit St. Petersburg 4-2 in the Champions League on Tuesday, after losing 3-0 to Hamburg the weekend before.
"It was a tough piece of work," Dortmund coach Juergen Klopp said. "Nuremberg will certainly get enough points (to escape relegation)."
The same cannot be said of Hamburg. After beating Dortmund in new coach Mirko Slomka's first game in charge last week, the side slumped to its ninth defeat in 10 games.
"We'll fight against relegation to the last day," Hamburg defender Marcell Jansen said.
The game was delayed for several minutes in the second half due to flares among the home fans.
Goalkeeping mistakes were responsible for both goals in Braunschweig. Moenchengladbach scored in the 25th when Braunschweig 'keeper Daniel Davari turned Raffael's corner into his own net.
The home side equalized in the 52nd when Marc-Andre ter Stegen -- who is reportedly joining Barcelona at the end of the season -- allowed Filip Daems' back pass slip behind and into the goal.