Defending champions Bayern Munich crashed to a shock 3-1 defeat at Bayer Leverkusen on Saturday, allowing Borussia Dortmund to extend their lead at the top of the Bundesliga table to seven points.

Superb second-half goals by Leverkusen's Leon Bailey, Kevin Volland and Lucas Alario inflicted only a fourth league defeat this season on second-placed Bayern as Dortmund added a point to their lead despite drawing 1-1 at Eintracht Frankfurt.

Bayern had their seven-match winning streak in the league ended abruptly and lived dangerously early on at Leverkusen, whose forward Kevin Volland fired a shot off Mats Hummels arm, but the referee waved away furious penalty appeals.

Bayern's in-form midfielder Leon Goretzka showed why head coach Niko Kovac has to start him in his star-studded line-up with a superb opening goal.

When Leverkusen winger Julian Brandt broke clear, it was Goretzka who sprinted back to win the ball.

Bayern countered quickly and, with Leverkusen failing to get back, Goretzka sprinted between two defenders to head home his fourth goal in three games on 41 minutes for a superb box-to-box goal.

It should have been 2-0 at the break to Bayern as Robert Lewandowski put the ball in Leverkusen's net, but the video assistant referee ruled the effort marginally offside.

However, Leverkusen's fleet-footed attack hit top gear in the second-half, sparked eight minutes after the break when Jamaican winger Leon Bailey curled a free-kick past Bayern's reserve goalkeeper Sven Ulreich, in for thumb-injury victim Manuel Neuer.

The equaliser galvanised Leverkusen, who shredded the Bayern defence to leave Volland with a simple tap in on 63 minutes, then Argentinian striker Alario replaced Bailey and tapped home a Brandt cross on 89 minutes as Bayern failed to defend a counter attack.

Dortmund deserved a point at Frankfurt and went ahead after a fantastic run by Raphael Guerreiro, who dribbled past two defenders and drew a third to leave Marco Reus free to fire home unmarked on 22 minutes.

Dortmund playmaker Reus, who has hit 13 league goals and created nine more, could have scored four times in the first-half alone - twice firing wide and also clipping the bar.

Frankfurt drew level nine minutes before the break when Luka Jovic, the league's top-scorer with 14 goals, finally beat Dortmund goalkeeper Roman Burki, moments after seeing an effort saved, when he poked home a cross.

At the other end of the table, Nuremberg climbed off the bottom with a 1-1 draw at home to Werder Bremen as Johannes Eggestein's second-half goal was cancelled out by a late equaliser from Nuremberg's Swedish striker Mikael Ishak.

Hertha Berlin, who host Bayern in the last 16 of the German Cup on Wednesday, crashed to a 1-0 defeat in falling snow at the Olympic Stadium as towering Dutch striker Wout Weghorst scored Wolfsburg's winner after they had suffered back-to-back defeats.