Wilson collected 12 points in Sunday's final round to finish with 34 points. Lehman recorded 10 points to match Wilson as the pair headed to the 18th hole at Castle Pines Golf Club to begin the extra session.
Both lagged their birdie tries within two feet and converted the par putts. They were off to No. 9 for the second sudden-death hole.
Lehman and Wilson both found the short grass off the tee, but Lehman's second landed on the edge of the top of a bunker and stopped in the fringe 25 feet from the stick. Wilson hit an 8-iron from 160 yards to seven feet.
Lehman gave it a good effort, but his putt stayed above ground. Wilson's birdie putt poured right in the center of the cup and gave him his first PGA TOUR victory.
'It's fun to get up on a leaderboard and feel those nerves,' said Wilson, who pocketed $990,000 for the win.
For Lehman, this was an interesting tournament on several levels. He is the American Ryder Cup captain and 10 spots on his team will be finalized next week after the PGA Championship. Lehman will make his two captain's picks on Monday, but things could have gotten interesting on Sunday.
If Lehman would have won the tournament, he would have moved up to seventh on the points list with only one week to go. There has not been a playing captain since the 60s and the last captain to win on the PGA Tour during his tenure was Jack Nicklaus at the 1986 Masters.
Due to some indifferent approach shots in the playoff, Lehman won't have to worry about that, but the 47-year-old was certainly encouraged by his play this week.
'I'm very pleased with the way I hit the ball all four days,' said Lehman. 'Overall if you would have told me Thursday morning that I would have a chance to win, I'd be pleased.'
Daisuke Maruyama netted 13 points and tied for third place with Steve Flesch, who tallied six points on Sunday. The pair finished with 32 points in this unique tournament.
This event uses the modified Stableford scoring system, which places a premium on birdies, eagles and double-eagles. Players receive two points for a birdie five points for an eagle and eight points for a double-eagle. Players lose one point for a bogey and three points for a double-bogey or worse, with a par receiving a score of zero.
Wilson tallied three birdies for six points on his front nine, then closed the side out in style with a 12-foot birdie putt at the ninth. That gave him the lead with 30 points.
Wilson jumped to 33 points with a 13-footer for birdie at 11, but dropped a shot at 12. When Bubba Watson birdied the 14th and Wilson bogeyed 12, the pair was tied with 31 points.
It did not take Wilson long to reclaim the lead. He drained a 15-foot birdie putt at the 13th to get back to 33 points, but Lehman began his charge up the leaderboard.
Lehman amassed four points through 10 holes, but back-to-back birdies in the 12-foot range at 13 and 14 got him to 32 points. When Wilson drove into the right rough and could not save par at 15, the two were tied for the lead.
Wilson, playing ahead of Lehman, two-putted from 32 feet for a birdie at 17. Lehman knocked his second at the hole to 15 feet, but came up a foot short on his eagle try. He tapped in for birdie, then ultimately lost out on his first victory since the 2000 Phoenix Open.
For Wilson, this win has been a long time coming.
'It seems like every year I've gotten a little better,' said Wilson. 'This year I put myself into contention a few more times than the last few years, so I'm really happy with that.'
Stewart Cink moved up in the American Ryder Cup standings as he logged six points on Sunday to finish alone in fifth place with 31 points.
Watson, who was undone with a disastrous 17th hole, accumulated 11 points in the final round. He tied for sixth place with Jeff Brehaut (nine points) and Ian Leggatt (five points) with 30 points.
Overnight leader Zach Johnson struggled on Sunday. He lost one point and tied for 13th place with 26 points.