Hamburg - Bayer Leverkusen moved three points clear at the top of the German Bundesliga Saturday thanks to a 4-0 demolition of struggling Nuremberg while Bayern Munich lost ground after failing to break down a resilient Cologne side.

An early free-kick from Toni Kroos followed by a Simon Rolfes penalty and an Eren Derdiyok strike left Leverkusen in command at the break with Stefan Kiessling completing the rout midway through the second half.

The win sees Leverkusen move on to 20 points, three clear of SV Hamburg, who can draw level with them Sunday with victory over bottom side Hertha Berlin.

Schalke 04 sit third on 16 points thanks to a 2-0 win Friday against Eintracht Frankfurt while Bayern's scoreless draw with Cologne sees Louis van Gaal's side languish in seventh, eight points adrift.

Kroos gave Leverkusen the perfect start at the BayArena, curling in a free-kick after just two minutes.

The 19-year-old midfielder also played a part in Leverkusen's second shortly before the half-hour mark, powering into the Nuremberg penalty area before being felled by Jawhar Mnari.

Rolfes slotted home the resultant free-kick and with the Nuremberg defence now in tatters, Derdiyok made it 3-0 on 34 minutes after a neat combination with Kiessling.

Kiessling got onto the scoresheet himself on 68 minutes, nodding home from close range.

Bayern dominated proceedings against Cologne and could have gone in front as early as the 11th minute but a Bastian Schweinsteiger header came back off the crossbar.

Schweinsteiger was unlucky again seven minutes before the break when another header deflected off teammate Miroslav Klose and onto the woodwork.

Van Gaal replaced Franck Ribery at half-time with Danijel Pranjic and Mario Gomez for Jose Ernesto Sosa but Cologne held on for a vital point.

Defending champions VfL Wolfsburg sit sixth on 13 points after coming from behind to secure a 1-1 draw away to VfL Bochum.

Vahid Hashemian put Bochum in front after 53 minutes but within 10 minutes, however, the home side were reduced to 10 men when Shinji Ono received his marching orders for a second bookable offence for a tackle on Wolfsburg captain Josue.

Dzeko took full advantage with 15 minutes remaining, heading home the equalizer.

Hoffenheim also lost ground on the leaders after losing 2-1 to Mainz.

Andreas Ivanschitz opened the scoring for Mainz after six minutes with a sweetly struck volley with Aristide Bance making it 2-0 with a header five minutes later. Andreas Ibertsberger got a late consolation effort for Hoffenheim.

In other action, Hanover 96 beat Freiburg 4-2 while later Saturday Borussia Dortmund visit Borussia Moenchengladbach. (dpa)