Serhou Guirassy scored four goals as Borussia Dortmund inflicted a 6-0 rout on Union Berlin at Signal Iduna Park.

Maximilian Beier was also on target for Niko Kovac's side, who recorded only their second victory in eight Bundesliga matches.

Dortmund broke through in the 25th minute when Julian Ryerson's shot deflected in via Diogo Leite, while Guirassy headed home Pascal Gross' cross to double the lead five minutes before the break.

The striker added his second with a quarter of an hour remaining, before completing his hat-trick five minutes later.

Guirassy headed in another Gross cross for his fourth goal, while Beier struck in the dying seconds to put the seal on Kovac's first league win in charge.

Data Debrief: Four-midable Guirassy and Gross

Scoring four goals in a match for the first time in his career, Guirassy became the third Dortmund player this millennium to do so in a Bundesliga game after Pierre-Emerick Aubameyang and Erling Haaland.

Gross, meanwhile, claimed four assists and is the third player to achieve that feat in a Bundesliga match since data collection began in 2004-05, after Christopher Nkunku and Szbabolcs Huszti.