Holmes birdied the 18th twice in a matter of minutes, first with a 13-foot putt to force the playoff, then with an 8-footer after a monster, 359-yard drive.

Holmes, whose victory as a rookie at the FBR in 2006 is his only other PGA Tour win, had blown a four-stroke lead and was one shot behind going in to the 18th. The far more seasoned Mickelson seemed destined for his third victory in the tournament and 33rd of his career.

But the 25-year-old Kentuckian smashed a 350-foot drive that landed near a fence far left of the fairway. He was awarded a drop, then hit his second shot out of the rough 13 feet from the pin to set up the putt that put him at 14-under 270 and forced the playoff with Mickelson.

Holmes' playoff tee shot went straight and deep down the fairway. He walked away from the drive like Barry Bonds after a home run. Holmes second shot came to rest just 8 feet from victory.

Mickelson, who birdied three of the final six holes of regulation, just missed a 28-foot birdie putt before Holmes made the winner. The victory was worth $1.08 million.

It was the first playoff in the event since Mickelson beat Justin Leonard in a three-hole playoff in 1996. That, coincidentally, was the other weekend that the Super Bowl was held in Arizona.

With the Super Bowl being staged some 30 miles down the highway on Sunday, attendance dropped to 71,805 on a chilly, overcast day. That's nearly 100,000 fewer than the record 170,802 who came Saturday for the biggest party day of the boisterous event.

Still, overall attendance for the event was a record 538,356.