The Dutchman's had the chance to keep the title race alive against the league leaders but his 86th-minute penalty was saved by Dortmund goalkeeper Roman Weidenfeller at Borussia's Signal Iduna Park stadium on Wednesday.

The defeat leaves Bayern six points behind Dortmund with just four games remaining.

"That is very bitter and very disappointing," said Robben.

"In the last three years I have converted 10 or 11 penalties in succession.

"That was the first one I have missed and, yes, that was really embarrassing."

Poland striker Robert Lewandowski had given Dortmund the lead with a 77th-minute goal before Robben was brought down by Weidenfeller nine minutes later in the area.

Saved

But Robben fired too close to the keeper who gratefully saved the shot and the winger's misery was complete when he fired over the bar with the goal at his mercy just before the final whistle.

Bayern coach Jupp Heynckes refused to blame Robben for the defeat after the game.

"Normally, he is a very reliable penalty taker," said Heynckes.

"He has played well in the last few weeks and I don't blame him, he was the most annoyed by his miss."

But ex-Bayern president Franz Beckenbauer saw things differently.

"He is a world class-player, he will get over it, but for me, he should not have taken the shot," said Beckenbauer, who coached Germany to their 1990 World Cup win.

"As a coach, I had the rule that any player who is fouled doesn't shoot.

"Maybe that is no longer the rule with Bayern or maybe it has not got through to Holland yet."