Bill Haas fired a 5-under 66 on Sunday and secured a 3-stroke victory at the AT&T National.
Haas shared the overnight lead with three others before separating himself from the pack with a trio of birdies from the par-4 eighth at Congressional Country Club's Blue Course. He finished at 12-under-par 272 and notched his fifth career PGA Tour win.
"He played beautifully today," said tournament host and defending champion Tiger Woods, who sat out with an elbow injury. "He handled his business through the tougher stretch of holes and pulled away."
Roberto Castro, another overnight leader, carded a 2-under 69 and finished alone in second place at 9-under 275.
D.H. Lee shot 7-under 64, the low round of the final day, and jumped into a tie for third at 8-under. He ended alongside Jason Kokrak, who carded a 69.
Stewart Cink (67), 19-year-old Jordan Spieth (69) and Charlie Wi (71) finished fifth, sixth and seventh, respectively, at 7-under through 5-under, while Brandt Snedeker (71) and third-round co-leader James Driscoll (74) highlighted a group of five tied for eighth at minus-4.
"Starting the year out, I wouldn't have imagined ... I'm lucky to have a place to play," said Spieth, who has four top-10 finishes in just 13 starts with limited PGA Tour status this year. "I'm trying to get a win, and this is a great step forward for me."
Andres Romero, the other overnight co-leader, tripped to a 75 and ended in a tie for 13th at 3-under. Angel Cabrera (69) and Brendon Todd (72) also finished at 3-under.
Haas played his first seven holes at even-par on Sunday, and there was little separation at the top, as he was tied with Castro, Kokrak and Spieth at that point.
From there, Haas caught fire.
He played his remaining 11 holes at 5-under, beginning with a 10-foot birdie putt at the par-4 eighth, which gave the 31-year-old a lead he didn't relinquish.
Haas made it two in a row when he hit his approach inside 12 feet and birdied the par-5 ninth, then completed the hat trick around the turn with another gain at the par-3 10th.
The trio of successive birdies gave Haas a 2-stoke lead over Castro, who had two birdies and a bogey through 10.
Castro picked up a birdie at the par-4 14th, but Haas did as well; in unlikely fashion, as his misfired 9-iron bounced off a mound of rough to the right of the green and landed within 10 feet of the cup.
Haas pushed his lead to three with a tap-in birdie at the 16th, then parred out, draining a 3-footer at the last to lock up the win.
"I just kept the ball in front of me," Haas remarked. "Nothing too crazy."
NOTES: Haas had missed three of four cuts entering this tournament ... He was the only player with four rounds under par for the week ... His best previous finish on tour this season was a tie for third at the Northern Trust Open, which was also the scene of his last victory in 2012 ... Haas was making his 229th PGA Tour start. His father, Jay, won his fifth PGA Tour event in his 181st start.