Tiger Woods gained revenge on US PGA champion Y E Yang to clinch the Presidents Cup in San Francisco tonight as the United States defeated the International team 19.5 to 14.5.

Woods sank the winning putt at Harding Park to complete a 6 and 5 demolition of the Korean, who in August at Hazeltine National had become the first man to overhaul a 54-hole lead by the world number one in a major championship.

The victory in singles left Woods unbeaten in five matches this week, four of them partnering Steve Stricker, as the American team captained by Fred Couples got the better of its International rivals in the final day's 12 singles matches.

Not that Woods realised he had retained the Presidents Cup for his country.

"Did it really?" Woods asked. "Well, perfect. All I knew was that I was trying to get my point, that I was five up and trying to make it six.

"I didn't look at any boards, I saw we were down in six matches at one point so I just kept my head down and tried to sustain my own lead."

Captain Couples was full of admiration for the effort put in by Woods and also Sean O'Hair, who had hammered Ernie Els of South Africa 6 and 4.

"Today he won a huge battle," Couples said of Woods. "I couldn't be happier for him and for me to have him win the (decisive) point.

"The whole time, I needed him - it sounds stupid - to go 5-0. You never can assume anything but we were hoping he would get a point.

"Besides him, Sean O'Hair came up huge to beat Ernie, who's a world class player. Sean was a guy we had a hunch about and he came up big today."

Having led Norman's side 12.5 to 9.5 at Harding Park after three days of foursomes and fourballs matches, the Americans had needed just five points from the 12 singles rubbers on the final day of the eighth Presidents Cup, the Internationals having only won one previous meeting, back in 1998.

With a half point on the scoreboard and no halves available in singles play while the matches could decide the outcome, no repeat of the 2003 tie was possible as the Americans looked to close out a sixth victory in this Ryder Cup-style event.

And the home side went the right way about mopping things up early, captain's pick Hunter Mahan coming from behind on the front nine against Colombia's Camilo Villegas to win 2 and 1 in the first match and Open champion Stewart Cink overcoming Norman's fellow Australian and captain's pick Adam Scott 4 and 3 in the second match.

When another Australian, Robert Allenby, missed a short putt on the 15th hole, Anthony Kim's 5 and 3 victory put the Americans within two points of victory.

That victory was assured with Sean O'Hair beat South Africa's Ernie Els 6 and 4, leaving Woods to secure victory and gain revenge over Yang.

With the outcome decided, Canada's Mike Weir halved his match with Justin Leonard, while Geoff Ogilvy denied Stricker a perfect record, the Australian winning their rubber 2 and 1.

Tim Clark of South Africa defeated Zach Johnson 4 and 3, while 18-year-old Japanese rookie and captain's pick Ryo Ishikawa beat American veteran Kenny Perry 2 and 1 and Masters champion Angel Cabrera secured his first point of the week with a 4 and 3 win over Jim Furyk.

Vijay Singh and US Open champion Lucas Glover halved their match, meaning Glover avoided being the only American not to contribute to the scoreboard and Phil Mickelson completed an unbeaten week in his eighth Presidents Cup when he beat Retief Goosen of South Africa 2 and 1.