New Delhi: Striker Kai Havertz’s two goals and one each by Mitchell Weiser and Kerem Demirbay helped Bayer Leverkusen to stay in the hunt for a top-four finish in the Budesliga.
The result left Bayer fifth on 50 points from 26 games, one behind fourth-placed Leipzig and eight adrift of leaders Bayern Munich.
Werder, who suffered a record-extending seventh straight home defeat, stayed 17th on 18 points from 25 matches.
With no spectators present in the stadium as part of the COVID-19 precautions, the game descended into a lull before a frantic five-minute spell produced three goals midway through the first half.
Havertz fired Leverkusen ahead in the 28th minute when he rose above his marker at the far post and headed past keeper Jiri Pavlenka after a darting run and cross by Moussa Diaby.
Havertz was left completely unmarked to head home from eight metres after Kerem Demirbay floated in an inch-perfect free kick and Bremen fell apart in the second half as the visitors carved them open almost at will.
Defender Weiser made it 3-1 in the 61st minute when he powered in a close-range header after another fine assist by the lively Diaby and Leverkusen missed several chances before Demirbay sealed the rout.
Substitute Karim Bellarabi waltzed his way through a static home defence before he released Demirbay with a clever pass which left the latter with a simple task of beating Pavlenka with a dinked finish.