By Norman Dabell

ST QUENTIN, France (Reuters) - German Martin Kaymer won the French Open on Sunday after defeating former European number one Lee Westwood of Britain in a sudden-death playoff.

Kaymer took the 930,000 dollars first prize with a par at the first extra hole after both men had finished on 13-under-par 271, three strokes better than Briton Ian Poulter.

After signing for a three-under 68, the young German fared better at the tough finishing hole at the National in the shootout.

His ball just carried the lake and he was able to chip and putt from 18 feet, while Westwood, who had matched his 72 hole score with a 65, saw his ball slide into the water.

A series of lengthy putts, the longest an 84-footer on the eighth, proved the key in the end to 24-year-old Kaymer's third European Tour victory. Westwood, though, with a similar hot putter as he ran in seven birdies came close to ending a run of four second places in 2008.

A bogey on the long 14th subsequently cost Westwood the chance of outright victory. Kaymer's big chance came even later as he missed a birdie putt of only seven feet on the penultimate hole.

"That was one of my few misses because my putting had been great all week," Kaymer, who had equaled the course record 62 to lead the first round, told reporters. "I made so many putts from everywhere."

Victory takes Kaymer to fifth on the European money list and he is sure to move from 28th place into the world top 20.

"The world ranking is the important thing to me," added Kaymer. "I've never been so high before."

Westwood hid his disappointment with his best result of the season.

"Playoffs are fickle. Martin carried the water by a foot and my ball went in by a foot," the 2000 European number one said.

"But I putted better today and that's what I need. Then I'll be winning events by a couple of shots and not needing playoffs."

A furious Poulter (67) blamed a press photographer for his round faltering over the closing holes, vowing he would not return to the tournament in future after finding the lake on the 15th.

"It was a tournament I wanted to win and some stupid cameraman makes it difficult for you," Poulter told reporters.

"I had a simple wedge into 15 and he fired off three shots on my way down (in the swing) from 25 yards away. It was very difficult to get my mind back on the job then.

"I'll not be back. It's a shame but that's what happens when you let novices come in and ruin our livelihoods."

Overnight leader Rafa Echenique's chances of a maiden victory looked slim when he ran up a triple-bogey seven on the 15th.

When he repeated the feat on the 18th he plummeted to 13th place with a 77, eight strokes away from the playoff. Only a week before, the young Argentine albatrossed the final hole in Munich to take second place in the BMW International Open.

(Editing by John Mehaffey)