BVB never looked troubled as they took three points from Bremen, running out a comfortable winner thanks to strikes from Reus, Gotze, Santana, Lewandowski and Kuba.An early goal set Borussia Dortmund on the way to a crushing victory that never looked in question, as the club strolled to a 5-0 triumph over Werder Bremen in Nuri Sahin's first game back at his old club. Marco Reus looped in a free kick in the opening minutes, and Jurgen Klopp's charges never released their grip on proceedings as further goals from Mario Gotze, Felipe Santana, Robert Lewandowski and Jakub Blaszczykowski ensured three points for the Bundesliga holder.
In desperate need of three points to keep up the chase on Bayern Munich and Bayer Leverkusen at the Bundesliga summit, Dortmund could not have asked for a better start on Saturday afternoon. Roberto Lewandowski was felled on the edge of the box with eight minutes on the clock, and Reus stepped up to float a delightful free kick into the top right corner, with Sebastian Mielitz immobile between the posts.
Werder showed plenty of industry and fight during the first half, but struggled to translate the exertions into clear chances during the first 45 minutes. Nils Petersen had one of the few opportunities that fell to the home side with a shot that was dragged wide of the upright, but otherwise it was BVB which continued on top in the match's early stages.
Dortmund's rapid attacking was giving the Bremen back line lots of trouble, and the side was 2-0 up before 20 minutes were on the clock. Kevin Grosskreutz did well to make space after receiving a lovely ball from Ilkay Gundogan, and his pass found Gotze on the edge of the area. The youngster received a stroke of good fortune as his shot rebounded off a Bremen boot, looping over a despairing Mielitiz and into the roof of the net.
Dortmund finished the half in clear control, and Mats Hummels was left wondering what might have been as he burst through the defense only to lay off a wayward pass when the goal beckoned. Bremen had not been outplayed, but BVB's clinical finishing in front of goal handed the champion a decisive advantage as the teams went in for the break.
The second half was barely three minutes old when the game was effectively ended as a contest. Petersen failed to keep track of Santana at an early corner, and paid dearly as the Brazilian connected with the cross and headed home to further extend Dortmund's advantage. The striker tried to make amends with a strong run down the right side, but he blasted a shot well wide as Bremen looked to do the impossible and find a way back into the match.
Roman Weidenfeller was finally called into action one hour in when he tipped over a header from Petersen, but it was otherwise plain sailing for the away team which enjoyed a three-goal cushion. The Werderaner continued to battle valiantly in their efforts to get something out of the game, but there was no way through and Dortmund strolled to a comfortable, impressive victory to keep themselves in the Bundesliga hunt.
Lewandowski pitched in with a simple tap-in 10 minutes from time to cap an impressive display.
One of the evening's biggest ovations was reserved right at the end for Nuri Sahin, who came on in his first appearance since returning from Real Madrid, but Dortmund was not finished. Fellow substitute Blaszczykowski added insult to injury with another goal, finishing powerfully with Werder in disarray.
Jurgen Klopp's men remain in third place after Bayern and Leverkusen's victories, still 12 points from the summit currently occupied by Die Roten. Bremen, meanwhile, holds on to 12th although the club could slip down depending on Sunday's results in round 18.