FINAL LEADERBOARD -6 T Woods (US) -5 C DiMarco (US) -4 P McGinley (Ire), V Singh (Fiji), R Palmer (US) -3 L Donald (Eng), D Howell (Eng), K Perry (US)

The world number one, who led from the first round, carded a final-round 71 to finish on six under, one better than fellow American Chris DiMarco.

It was Woods' 10th win in 20 World Golf Championships starts.

Ireland's Paul McGinley claimed a share of third, while England's Luke Donald and David Howell were tied for sixth.

Woods struggled early in his round, twice missing three-foot par putts for pars, as he slipped behind fellow third-round leader and playing partner Kenny Perry.

But Perry's game disintegrated as he reached the turn, dropping five shots in six holes from the ninth and he never recovered.

McGinley recovered superbly from a double bogey at the 12th to briefly join Woods and DiMarco at the top of the leaderboard with a birdie at the 16th.

Tiger is such a skilful player no shot is impossible Paul McGinley

But disaster struck at the next hole when he found trees from the tee and dropped a shot.

The Irishman needed a birdie at the 464-yard last to keep his hopes alive but his 40-foot chance failed to drop and he had to be content with joint third.

McGinley, who had two late bogeys to lose the BMW Championship at Wentworth in May, said afterwards: "I gave it away at the 12th - you can't afford to do what I did - but dug deep and rallied.

"Tiger, though, seems to have a shot every time he hits it in the trees. He makes some great escapes and is such a skilful player no shot is impossible."

Having gone in front with a birdie at the 667-yard 16th, Woods needed to par the last two holes to get the better of DiMarco, who he beat in a play-off for the Masters earlier this year.

I kept leaving myself downhill downwind putts Tiger Woods

Another play-off was a possibility when his final drive headed into the trees, but he found a gap to the green and was able to put aside his earlier putting difficulties to secure a fourth victory in seven years at Firestone.

"I was just trying to get to six under somehow. My realistic chance was 16 and I was able to take it," said Woods.

"I've had that putt three or four times and have missed it. This time I threw it out a bit wider. I thought I had overdone it but it started curling and lipped in. It was sweet.

"I hit the ball beautifully, but either good putts didn't go in or I hit some atrocious ones.

"The course was playing so tough, though, and I kept leaving myself downhill downwind putts."

Donald, after a disappointing third-round 74, came back with a 67 on Sunday and would have been joint third alongside McGinley, world number two Vijay Singh and young American star Ryan Palmer but for a closing bogey.

Instead he slipped back to three under with Howell, who was playing in only his second event back from two months out with a torn abdominal muscle.

Colin Montgomerie and Jose Maria Olazabal were only one further back in a tie for ninth, making five Europeans in the top 12.

The victory was the 45th of Woods' career and moved him past Walter Hagen on the all-time list. Billy Casper is the next man in his sights with 51 wins.