Robert Lewandowski's brace helped Bayern Munich to round off the season with the domestic double after beating Leipzig 3-0 in the German Cup final at outsold Berlin Olympia stadium on Saturday.

Two goals from Robert Lewandowski and one by Kingsley Coman were enough to secure Bayern's 12th domestic double and their 19th German Cup title.

Leipzig caught a bright start and had a promising chance in the opening period when Yussuf Poulsen's header forced Bayern goalkeeper Manuel Neuer into action with 11 minutes played.

Bayern grew into the game as the clock ticked and shocked Leipzig with the opener against the run of the play in the 29th minute after Robert Lewandowski headed home David Alaba's cross into the box.

Bayern dictated the pace to produce goal scoring opportunities in the closing period of the first half as Kingsley Coman and Mats Hummels came close.

Ralf Rangnick's men started well into the second half and they should have leveled the scores in the 48th minute when Emil Forsberg was unable to overcome Manuel Neuer following a one-on-one.

Both sides exchanged attacks at each end of the pitch as Lewandowski tested Leipzig goalie Peter Gulacsi before Niklas Suele blocked Timo Werner's shot on target on the goal line.

However, Bayern increased the pressure and doubled the lead in the 77th minute when Coman slotted home from inside the box into the far post corner to take the wind out of Leipzig's sails.

The "Bavarians" were still not done with the scoring and put the result beyond doubt in the 85th minute through Lewandowski, who wrapped his brace.

"Leipzig is a tough opponent. They gave us a hard fight in the opening period of each half but the bottom line is: we secured a deserved win," Bayern Munich's head coach Niko Kovac said.

"Of course we are disappointed now as we hoped for different outcome of the game. However, I think we played a great season overall and should not forget that," Leipzig's CEO Oliver Mintzlaff said.