FINAL ROUND LEADERBOARD:
US unless stated
-12 A Kim -10 F Jacobson (Swe) -9 R Pampling (Aus) J Furyk, R Allenby (Aus), D Wilson, N O'Hern (Aus), T Armour III
Kim also won the Wachovia Championship
Anthony Kim won his second tournament of 2008, firing a final round 65 to claim the ATT National at the Congressional Country Club course.
The 23-year-old finished with a bogey- free round to end on 12 under, two clear of Sweden's Fredrik Jacobson.
Australians Rod Pampling, Nick O'Hern and Robert Allenby were among a group of six tied for third on nine under.
Tom Pernice Jnr, the leader after three rounds, finished tied ninth after a final-round 72.
Kim, who started his final round three adrift of Penrice, became the first American under the age of 25 to win two PGA Tour events in the same year since Tiger Woods.
I'm staying away from bad people and staying away from bad places
In May, Kim, then 22, became the youngest winner on the PGA Tour in more than six years with victory at the Wachovia Championship.
Kim, who revealed he had spent too much time enjoying himself off the course last year, attributed his successes in 2008 to a more mature attitude.
"My preparation and work ethic couldn't have gotten any worse," Kim said. "So it had to get better.
"And I don't know what tournament it was, but I realised that this isn't way want to do. If I'm going to finish 35th, 25th, every single week, I don't want to play golf.
"I'm making a lot better decisions off the course now. I'm staying away from bad people and staying away from bad places."
Jacobson, 33, came home in 30 shots to finish with a 65, second place and with it a spot in the Open Championship at Royal Birkdale from 17 July.
Open exemptions have also been handed to Kenny Perry and Rocco Mediate, though Perry has stated that he does not intend playing the Open.
His spot is set to go to the highest ranked player not already in the field, currently Colombian Camilo Villegas.