Bayern Munich forward Robert Lewandowski scored a hat-trick as the Bundesliga leaders obliterated Hamburg SV 8-0 on Saturday to stay five points clear at the top and equal their opponents' heaviest league defeat.

The Pole, who has netted 19 times in the Bundesliga, struck twice in the first half and slotted in his third goal in the 54th minute after Arturo Vidal had put the hosts ahead in the 17th.

Hamburg had pledged to put up a fight, pointing to their three-game unbeaten run before Saturday, but looked frozen as they conceded another goal by David Alaba in the 56th.

Substitute Kingsley Coman scored twice in five minutes and Arjen Robben scored on the break with Hamburg capitulating and equalling their heaviest Bundesliga defeat.