Patrick Makau breaks Haile Gebrselassie's marathon world record in Berlin

Patrick Makau retained the Berlin men's marathon title in a world record time.

The Kenyan finished in a time of two hours, three minutes and 38 seconds to shave 21 seconds off the record set by Haile Gebrselassie on the same course.

The Ethiopian great failed to finish having experienced apparent stomach problems around the 27km mark.

"In the morning my body was not good but, after I started the race, it started reacting very well. I started thinking about the record," said Makau.

"I didn't have any problems in the race. Last year I had some problems with my soles inside my shoe, but today everything went very well."

Gebrselassie, the 38-year-old double Olympic champion at 10,000m, had also been looking to post a fast time and ease the pressure on him to qualify for the Games ahead of strong Ethiopian rivals.

But he found himself forced to step off the road midway through the race as Makau, sensing the Ethiopian great was struggling, upped the pace.

Gebrselassie set the previous world record time with a mark of 2:03.59 in the third of his four consecutive Berlin victories between 2006 and 2009.

However, this year he halted for a full minute as his hopes of a quick time evaporated, then pulled out for good at the 35km mark.

"He was still feeling good at 25km but then his lungs started tightening up. He could not breathe - we don't know why," his agent Jos Hermens said.

Hermens added that Gebrselassie suffers from asthma and is allowed to take medicine, but had not taken any because he had not had any problems for months.

"Maybe this was a mistake, but he felt fine before, his preparation was good," he said.

"Qualifying [for London 2012] may be a problem now, we don't really know where to get it."

Gebrselassie is now expected to head to Dubai in a bid to ensure he reaches the London Olympics.