Thomas Mueller's strike on the hour, a Robert Lewandowski penalty, Thiago Alcantara's cracker and Ivan Perisic's header meant the champions on Sunday took full advantage of Borussia Moenchengladbach's 2-0 defeat at Schalke on Friday and leap-frogged the Foals.

Bayern lie four points behind leaders RB Leipzig, who won 3-1 at home to Union Berlin on Saturday.

Fourth-placed Borussia Dortmund, whose new signing Erling Braut Haaland scored a hat-trick on debut in a 5-3 win at Augsburg, are three behind Bayern after 18 games.

"We wore Hertha down and the gaps were a bit bigger in the second half. We were a bit too patient in the first half," Mueller told Sky.

Hertha coach Juergen Klinsmann, who managed Bayern for an ill-fated season in 2008-09, had a scare in midweek when he was told his coaching licence needed to be renewed but the documents required were at his California home.

The former US coach, appointed at Hertha in November until the end of the season, managed to get the paperwork submitted and was cleared on Saturday to stay as coach against the Bavarians.

"If you are forced to drop deep, then it is hard to play good football," Klinsmann said after Hertha's run of a four games without defeat came to an end.

Paderborn welcomed Leverkusen in the late game knowing a win would lift them off the bottom.

But those dreams soon evaporated with Kevin Volland scoring twice in four minutes in the opening quarter to set up a 4-1 win for the sixth-placed side, who trail Dortmund in the final Champions League place by two points.

Julian Baumgartlinger bagged the third before halftime after some poor goalkeeping.

Dennis Srbeny's goal for Paderborn on 51 minutes never looked like sparking a comeback and Kai Havertz's deflected finish put the icing on the cake for Leverkusen.

Paderborn remain three points behind Fortuna Dusseldorf in the second automatic relegation spot and five adrift of Werder Bremen in the relegation playoff berth.

Australian Associated Press