Padraig Harrington went toe-to-toe with Tiger Woods at the WGC Bridgestone Invitational before a meltdown at the 16th cost the Dubliner his chance of the title.
Harrington started the day three shots clear of the world number one, but surrendered that lead inside four holes and trailed by two shots after 11.
But he battled back to lead by one with three holes to play, only to take eight at 16 and open the door for the world number one to claim a seventh title in the event at Firestone, Ohio.
It took Woods just four holes to draw level with his playing partner in the final group at 10-under-par.
The Irishman started steadily with four pars, but Woods snaked in a 24-foot eagle putt at the par five second to cut the lead to one.
At the fourth, Harrington narrowly missed a birdie try from 17 feet and Woods immediately rolled in his own birdie putt from 14 feet.
Woods' putter was as hot as the weather and when he sent down his second birdie putt in a row at the fifth, this one from 27 feet, the world number one moved to the top of the leaderboard at 11 under, already four under for the day.
Harrington parred every hole on the front nine but a birdie from Woods at nine got him out in five-under 30 and he led by two at the turn.
But after both men parred the 10th, the momentum suddenly changed.
Harrington picked up his first birdie of the day at 11 to cut the lead to one, with Woods forced to make a seven-foot par putt.
But the American could not get away with overshooting the green at 13, failing to get up and down and making his first bogey of the day.
He immediately made another at 14 after finding two bunkers and when Harrington - who himself had been in big trouble - holed a 15-foot par putt, the Dubliner had the lead once more.
Both men made par at the short 15th, and both missed the fairway on the 667-yard par five 16th. But Woods fired his third shot stone dead for a birdie four. Sky Sports analyst Howard Clarke described that eight iron as one of the best shots he had ever seen.
Harrington missed the green with his third and then chipped through into the water. He could not find the green with his sixth from the other side of the pond and an eight meant he now trailed Woods by three shots.
Just one hole - in fact one poor shot - had gift-wrapped Woods his seventh Bridgestone title and he added a final flourish with a birdie at the last.
It was also his 16th World Golf Championship win and his 70th PGA Tour title.
Harrington - who will defend his USPGA crown at Hazeltine next week - had to settle for a share of second place alongside Australia's Robert Allenby, who shot a closing 66.