Poland striker Robert Lewandowski scored his 20th goal of the season in the second-half to give Dortmund three more priceless points and open a considerable gap over second-placed Bayern.

Dortmund took their chance when wing Kevin Grosskreutz's shot took a significant deflection off Lewandowski on 77 minutes.

But there was drama four minutes from time when Dortmund goalkeeper Roman Weidenfeller felled Dutch winger Arjen Robben in the penalty area.

The Netherlands star picked himself up to take the penalty, but he fired too close to the Borussia captain who saved the strike and was immediately mobbed by his team mates.

Both sides hit the cross bar with time almost up as Robben squandered a golden chance by shooting over with the goal at his mercy.

Lewandowski also hit the post after he chipped over Bayern goalkeeper Manuel Neuer just before the final whistle.

It was Dortmund's 24 consecutive game without defeat - their last Bundesliga loss coming last September against Hanover - and Dortmund's fourth straight win over the Bavarians, who will meet them again in the German Cup final on May 12.

Bayern coach Jupp Heynckes must now rebuild his players morale quickly as they face Real Madrid next Tuesday in the Champions League semi-final, first-leg, and before that host Mainz on Saturday in the Bundesliga, while Dortmund are at Schalke.

The third-placed Royal Blues suffered a shock 4-1 defeat at mid-table Nuremberg which leaves them six points behind Bayern.

Hamburg's woeful form continues as they were thrashed 4-0 at Hoffenheim to leave them with just two wins from their last ten games and only two points above the relegation places.

With just four games left, Kaiserslautern slumped to a 3-1 defeat at Bayer Leverkusen and they could be relegated if they lose at Nuremberg on Saturday as they currently lie 10 points from safety at the foot of the table.

Hanover enjoyed a 2-0 win over Wolfsburg to go seventh and back amongst the Europa League places for next season.

On Tuesday Borussia Moenchengladbach's hold on the fourth and final Champions League spot had weakened as they were held 2-2 by 10-man Werder Bremen.

Moenchengladbach - who have turned things round remarkably from avoiding relegation last season through a play-off - still hold a seven-point lead over VFB Stuttgart with four games remaining.

However, as their form has tailed off, Stuttgart's has got better and better and Tuesday's 3-1 win over struggling Augsburg was their eighth game without defeat, a run which has seen them record six wins and two draws and score 22 goals.

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