Tiger Woods and Rocco Mediate go head-to-head in an 18-hole play-off for the US Open title at Torrey Pines later today but England's Lee Westwood believes he can still be a major winner despite the lasthole heartbreak which prevented it becoming a three-man showdown.

Westwood faced a 20ft birdie putt on the final green to join the two Americans on one under par.

It pulled up short, leaving the former European No1 still searching for his maiden major championship. But the 35-year-old Ryder Cup star refused to dwell on his disappointment.

"It's sickening not to be in the play-off but I'm very positive," said Westwood, whose preparations were disrupted by the tonsillitis that forced him to quit five holes into his second round at the BMW PGA Championship at Wentworth three weeks ago.

"I only did a bit of chipping and putting because physically I wasn't up to hitting balls for two or three hours at a time. So if you'd have said I'd have a 20-footer to get in a play-off for the US Open I would have been surprised.

"But I got into contention and I had a good chance. While I'm disappointed with the outcome I think I've proved to myself and a few others that there is a major championship in me."

Westwood's two-over-par 73 left him level par for the tournament and one shot shy of playing partner Woods and Mediate, the 45-year-old who only made the starting line-up after coming through qualifying by way of a play-off.

Mediate, two behind overnight, returned a level-par 71 in the penultimate group and was then forced to fret as Woods and Westwood come to the par-five last, both needing a birdie to force a tie.

Both found bunkers off the tee and neither reached the green in two. But it was Woods, clearly in discomfort from knee surgery performed nine weeks ago, whose putter was hot.

Mediate watched the 15ft-birdie putt creep in and sighed, "Unbelievable". But having recovered from a back injury that threatened his career four years ago, he had reason to remain upbeat for the battle to come.

He said: "I get to play the national Open against the best player on earth, that maybe ever played. To go up against the best player in the world and have a chance to beat him, there's nothing else you could ask for, period."

Unfortunately for Mediate, form and statistics favour 32-year-old Woods in a big way.

He started the last day holding a oneshot advantage, and history shows that Woods has won all his 13 majors when leading going into the final round. He has also won his two previous playoffs for major titles, beating Bob May for the US PGA Championship in 2000 and Chris DiMarco at the US Masters in 2005.

Yet it took a piece of typical Tiger magic to force a fifth day's play at the spectacular course clinging to the cliffs above the Pacific near San Diego.

His birdie chance at the last was as difficult-as they come. Woods said: "That was actually one of the worst parts of the green, it's so bumpy down there.

"I just kept telling myself two and a half balls outside the right, but make sure you stay committed to it, make a pure stroke and if it plinkos in, or plinkos out it doesn't matter, as long as I make a pure stroke.

"And I did. I hit it good. It took forever to break, but it finally snuck in there at the end."

He refused to blame his last-round 73 on his weak left knee. "Just bad swings," he said.

But he admitted that before today's play-off he would need extensive treatment to an injury that may yet force him to withdraw from next month's Open Championship. He said: "It will take a lot of icing to try to get the swelling out and make sure I have a range of motion."