The South African sank a 2-foot par putt on No. 18 to finish at 9-under 271. He earned his first PGA Tour title since the 2009 Byron Nelson Championship and sixth overall.
Y.E. Yang birdied the final hole for a closing 66 to finish 8 under. Jerry Kelly, who played with Sabbatini and Yang in the final threesome, shot a 67 and took third at 7 under.
"Usually if you're in front, if you're running away from somebody, you tend to be a bit nervous," the South Korean said through an interpreter. "But in Rory's case, apart from No. 14, he seemed really calm. I commend him for being, I guess, so emotionally stable. I wasn't." Sabbatini started the final round ahead by five shots, and was still in front by five when he finished No. 8. But Yang was within one stroke seven holes later, thanks to birdies on Nos. 12 and 14 and two bogeys by Sabbatini.
"Rory did what he had to do to hold us off," Kelly said, "and we just didn't hit it good enough to make enough birdies." Then came treacherous Nos. 15-17, the water-laden stretch known as the Bear Trap. But there would be no collapse by the leader.
"Luckily I had enough of a cushion that I didn't get too concerned," Sabbatini said. "I knew going into today that if I shot even par, it was going to be tough to catch." A change in putters before the tournament gave Sabbatini's game a lift, and the new club came through again on No. 16 when he sank a 16-foot birdie putt to go back up by two.
Then he put his tee shot on the dangerous par-three 17th in the middle of the green.
Moments later, the horn sounded to signal a stoppage in play because of lightning in the area. The leaders found refuge in a van as heavy rain fell during a 28-minute delay.
But the threat to Sabbatini's lead had passed, and when play resumed he easily closed out the win.
Lee Westwood, who fell to No. 2 in the rankings behind Martin Kaymer on Feb. 28, shot 70 and tied for 29th. He needed a top-three finish to regain the top ranking.
Graeme McDowell shot a 64, matching the lowest score in the event since it moved to PGA National in 2007, and was 2 under for the tournament.
The average round was 2 1/2 strokes above par. Since the beginning of 2010, only last year's US Open at Pebble Beach has had a higher average - 4 over par.
Sabbatini is known for his fiery personality, outspoken nature and occasional digs at Tiger Woods, who skipped the event. But Sabbatini's demeanor was even-keel from the time he took the lead to stay on the front nine Saturday.
"I'm a passionate golfer," he said. "I love the game of golf, and I've had my moments. I'm not proud of everything I've done out here, but I'm trying to learn. I'm trying to be a role model for my children, and I know as my wife has said to me, I wouldn't want my son doing some of the things that I've done in the past." The Sabbatinis have three children ranging in age from 7 years to 5 1/2 months.
Dad started the final round up by five shots, and after No. 8 the lead remained the same. But Yang was within one stroke seven holes later, thanks to birdies on Nos. 12 and 14 and two bogeys by Sabbatini.
