Champions Dortmund wallop Wolfsburg
Mario Gotze 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.
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 Jurgen Klopp told reporters. "This throws a bad shadow over the game.
"We played a very good game and it was not the result that made me happy but the way we created the goals. We are in with the top teams now and we feel good being up there."
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 Monchengladbach.
Cologne were 2-0 up at half-time but Peruvian Pizarro hauled Werder back into the game before scoring the winner with five minutes to go, slotting the ball 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.
Monchengladbach 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.
Champions League combatants Bayer Leverkusen squandered a two-goal lead in the late match to finish 2-2 at home to battling Hamburg SV who have now drawn all three league games under Thorsten Fink.
Papiss Demba Cisse converted a stoppage-time penalty as Freiburg triumphed 2-1 at Nuremberg to move off the bottom.
In Dortmund, Wolfsburg offered little resistance against the hosts who cruised into a 2-0 half-time lead thanks to goals from Gotze 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 metres.
Lewandowski added another goal with a chip over goalkeeper Diego Benaglio after a lightning-quick break and Germany international Gotze completed the rout with 12 minutes left.