Tournament host Tiger Woods saw off defending champion Anthony Kim and held off a last-round charge from Hunter Mahan to win the AT&T National at Congressional Country Club. It was his 68th PGA Tour win and the 79th worldwide victory of his career.
Woods collected his third victory of the year, having won Arnold Palmer's event at Bay Hill in March and Jack Nicklaus' Memorial last month, by winning his own tournament by one stroke from Mahan with a final-round three-under-par 67.
Mahan had earlier shot a 62 that matched Kim's course-record round from Thursday and took the American to 12 under, but Woods moved in front with a birdie at the 16th and held onto his lead down the final stretch.
The world number one had been paired with Kim in the final group in Bethesda, Maryland, one-shot leaders at 10 under par over fellow Americans Michael Allen and Cameron Beckman.
Kim got off to a fast start with a birdie at the par-four first hole but had returned to 10 under with a bogey at the fifth, another par four, before Woods took control with back-to-back birdies at the par-four sixth and par-three seventh.
Kim appeared to be blowing his childhood dream of sharing the spotlight in contention with Woods when he bogeyed the eighth to fall three shots back of the 14-time major winner.
Both men sent down birdies, Kim at the ninth, Woods at the 10th but the 24-year-old defending champion was given a lifeline when his hero sent down a bogey five at the 11th, the hole that has been his nemesis on the par-70 Blue Course near Washington DC this week following two bogeys and a double there in previous rounds.
The 16th proved critical as Kim's chance of a successful defence disappeared as he missed from eight feet for birdie while Woods did birdie.
Woods finished at 13 under, a shot ahead of Mahan with Kim, having shot a 71 to finish third on nine under par.
Bryce Molder finished in fourth place on eight under with US Open champion Lucas Glover, level for the day, and Brandt Snedeker, who shot a 67, tied for fifth at seven under.
Vijay Singh had earlier shown that low scoring was possible with six birdies in his first 13 holes before two bogeys left the Fijian with a 66 to finish at six under for the tournament, tied for seventh with New Zealand rookie Danny Lee and Americans Jim Furyk and Cameron Beckman.
Justin Rose of England finished with a 69 to close at four under for a share of 16th, his first top-20 finish since the Masters, while Sweden's Daniel Chopra closed with a 71 to finish at three under in a tie for 20th.
England's Brian Davis and Martin Laird of Scotland posted a final-round 75 and 74 respectively, both men finishing on 11 over par for the tournament.
