BERLIN (REUTERS) - Bayern Munich's Robert Lewandowski and Arjen Robben scored twice each, as the champions crushed Hannover 4-0 in the Bundesliga on Saturday to go four points clear at the top of the table, while rivals Dortmund lost to Hamburg.

The Bavarians needed only 13 minutes to tighten their grip on the game, scoring first through Poland's Lewandowski, who controlled a superb Rafinha pass, and Robben pouncing on a Hanover mistake.

Lewandowski, who joined from Dortmund this season, benefited from another superb through ball in the 38th minute, this time form Juan Bernat, for his fourth league goal of the campaign.

Dutchman Robben also go this second goal, slotting in 11 minutes from time as undefeated Bayern moved up to 17 points.

Dortmund continued their disastrous league start, slumping to their fourth defeat in seven games when they lost 1-0 to relegation-threatened Hamburg on the back of their dominant Champions League win over Anderlecht.

Pierre-Michel Lasogga snatched the winner in the 35th minute following an Adrian Ramos mistake as Dortmund dropped to 13th on seven points, 10 behind Bayern after only seven games.

Dortmund posed little threat for much of the game and left it late to push for the equaliser. They failed, however, to beat Hamburg keeper Jaroslav Drobny in a frantic finale, with the veteran 34-year-old also doing well to deny Ramos from point blank-range in the 72nd.

Fellow Champions League club Schalke continued their roller-coaster season, losing 2-1 to Hoffenheim, who are second on 13 points.

Bayer Leverkusen salvaged a 2-2 draw against 10-man Paderborn with a 90th-minute Karim Bellarabi equaliser to drop to fourth on 12.