Sebastien Haller crowned his recent return from testicular cancer with an emotional goal for Borussia Dortmund Saturday, as Union Berlin knocked Bayern Munich off the top of the Bundesliga with a dramatic late win over Mainz.

Six months after a shock diagnosis which saw him miss the entire first half of the season, Haller finally opened his account for the club he joined last summer.

The Ivory Coast international's second-half header prompted wild celebrations among his team mates and helped Dortmund to a 5-1 win over Freiburg which kept them within two points of leaders Union.

Freiburg were reduced to ten men early in the first half after French full-back Kiliann Sildillia was booked twice in the space of two minutes.

Former Freiburg player Nico Schlotterbeck then heaped more misery onto his old club, his low snapshot beating goalkeeper Mark Flekken at the near post to give Dortmund the lead.

Schlotterbeck and Niklas Suele handed Freiburg a lifeline with some farcical defending on the stroke of half-time, allowing Lucas Hoeler to sweep in an unexpected equaliser.

Yet Karim Adeyemi wriggled his way through the Freiburg box to restore the lead with a neat finish early in the second half, before goals from Haller, Julian Brandt and Giovanni Reyna completed the rout.

Meanwhile in the capital, Union Berlin were working on their own fairytale as a late winner from US international Jordan Siebatcheu sent the high-flying minnows top of the table.

Former Union player Marcus Ingvartsen had cancelled out Kevin Behrens' first-half opener with a late penalty, but the Berliners rallied to claim a fourth straight win in 2023.

Eintracht Frankfurt also remained within four points of the top as France forward Randal Kolo Muani ran riot in a 3-0 win over hapless Hertha Berlin.

Having put Frankfurt ahead from the penalty spot, Kolo Muani ghosted through the Hertha back line to make it 2-0 before the half-hour mark, before Aurelio Buta added a third on the stroke of full time.

RB Leipzig's 0-0 draw at Cologne meant that Frankfurt remain a point adrift of the Champions League places in fifth.

Hertha have slumped to four straight defeats since the beginning of 2023, and are now five points adrift of safety after fellow strugglers Bochum cruised to a 5-2 win over Hoffenheim.

Philipp Hofmann gave Bochum a deserved lead with a tap-in before Philipp Foerster and Takuma Asano showed up a lifeless Hoffenheim defence to make it 3-0 by half-time.

Erhan Masovic and Moritz Broschinski added two more for Bochum after the break, with Christoph Baumgartner and Munas Dabbur grabbing consolation goals for the visitors.