Woods held what looked like an insurmountable three-shot lead with six holes left, but he dropped into a tie with Harrington at the Phoenix Country Club after a three-putt bogey at the 16th hole, and both players birdied the last to shoot 67 and finish at 9-under-par 271.

The playoff started at the par-5 18th, where Woods and Harrington made birdie putts, Harrington from 10 feet, Woods from seven.

They returned to play the same hole again, and this time Harrington prevailed, somewhat luckily, after his second shot hit a tree and kicked forward into a perfect lie in the rough, allowing him to hit his third shot to inside two feet.

When Woods missed his birdie chance from 10 feet, Harrington tapped in for the victory, his first in Japan.

Woods is 45-6 worldwide when leading into the final round, an impressive record by anyone's standards, but this loss was especially tough because he was on the verge of winning the event for the third successive year.

Woods, who took a five-week layoff before contesting last week's HSBC Champions at Shanghai, would have been only the second player to win the US$1.69 million Dunlop Phoenix three straight years. Japan's Jumbo Ozaki won it from 1994 to 1996.

Woods' worldwide playoff record is now 14-2, his only other loss in an official event coming at the hands of Billy Mayfair at the 1998 Nissan Open.

Japan's Shingo Katayama, who started the day two strokes off the pace, got off to a flying start with three birdies over the first six holes but a double bogey on the par-4 8th hole dashed his chances of making a run for the title.

Katayama won the Dunlop Phoenix in 2000 and was looking to become the first Japanese player to win since 2002, when Kaname Yokoo won.