Robert Lewandowski scored twice to move to 31 Bundesliga goals for the season as Bayern Munich thrashed Union Berlin to go seven points clear at the top.

The Poland striker has now scored 30 or more Bundesliga goals in a season five times, equalling the record set by Germany legend Gerd Muller.

His penalty made it 3-0 in first-half stoppage time, before tapping home Bayern's fourth just after the break.

Kingsley Coman and Tanguy Nianzou were also on target.

France winger Coman opened the scoring early with a swerving long-range drive that deceived Union Berlin goalkeeper Andreas Luthe.

Robin Knoche and Taiwo Awoniyi then both went close as the visitors threatened an equaliser.

But it was Bayern who scored next when Nianzou powered home a header from Joshua Kimmich's corner for his first goal for the club.

It was 3-0 when Lewandowski was fouled by Luthe in the area for a penalty, which he comfortably dispatched.

The 33-year-old wrapped up victory 90 seconds into the second half when he tapped home Jamal Musiala's low cross.

It was a convincing performance by Julian Nagelsmann's side, who had drawn their past two league games but remain on course for a record-extending 10th Bundesliga title.

Second-placed Borussia Dortmund can reduce the gap back to four points with a win at Koln on Sunday.