Mario Goetze scored twice and Shinji Kagawa, Sven Bender and Robert Lewandowski also struck as Dortmund chalked up their fifth win in six games to move up to 23 points, two behind Bayern who travel to promoted Augsburg on Sunday.

The only sour note for Dortmund came when defender Neven Subotic fractured a cheekbone in a collision with Sotiris Kyrgiakos and had to go to hospital.

"Neven needs surgery and will be out for about six weeks," coach Juergen Klopp told reporters. "This throws a bad shadow over the game." Claudio Pizarro bagged a hat trick as third-placed Werder Bremen came back from two goals down to beat Cologne 3-2 and go level on points with Dortmund and Borussia Moenchengladbach.

Cologne were 2-0 up at halftime but Peruvian Pizarro hauled Werder back into the game before scoring the winner with five minutes to go, slotting in at the far post for his 11th league goal of the season.

Visiting Cologne were down to 10 men for most of the second half after the dismissal of Henrique Sereno.

Moenchengladbach also have 23 points from 12 games after in-form striker Marco Reus scored twice in a 2-1 victory at Hertha Berlin.

It was a happy return to Berlin for Gladbach coach Lucien Favre who left Hertha two years ago.

Papiss Demba Cisse converted a stoppage-time penalty as Freiburg triumphed 2-1 at Nuremberg to move off the bottom.

Wolfsburg offered little resistance against Dortmund who cruised into a 2-0 halftime lead thanks to goals from Goetze and Kagawa.

Aleksandr Hleb cut the deficit for Felix Magath's side in the 60th minute but Bender then headed in for the home team from two meters.

Lewandowski quickly added another goal with a chip over keeper Diego Benaglio and Germany international Goetze completed the rout with 12 minutes left.