Bubba Watson conjured a miraculous par from pine straw to become only the third left-hander to win the Masters with an emotional playoff victory over Louis Oosthuizen at Augusta National on Sunday.

The American clinched his first major title with a two-putt par on the second extra hole, the par-4 10th, where South African Oosthuizen bogeyed after ending up just short of the green in two and failing to get up and down.

Both players had ended up well right off the tee, Oosthuizen gaining a fortuitous bounce off a tree before playing his second shot from the first cut of rough.

Although the long-hitting Watson ended up deep in the tree line, he had an avenue to the green and struck a superb high draw off the pine straw with a gap wedge for his ball to settle 10 feet from the pin.

After Oosthuizen had chipped up 15 feet past and narrowly missed his par putt coming back, Watson had the luxury of two putts for victory. His birdie attempt slid past the cup but the 33-year-old from Bagdad in Florida gathered himself and tapped in for victory before embracing his caddie.

"I never got this far in my dreams," a teary-eyed Watson said in the Butler Cabin before being helped into the revered green jacket by last year's Masters champion Charl Schwartzel of South Africa.

"It's a blessing," Watson added, after joining fellow left-handers Phil Mickelson (2004, 2006 and 2010) and Canadian Mike Weir (2003) as Masters winners.

A self-taught golfer who learned the game by hitting wiffle balls around his house, Watson became the eighth consecutive first-time winner of a major and the 11th in the last 12 championships played.

Oosthuizen, the 2010 British Open champion, had earlier spectacularly grabbed a two-shot lead with a stunning albatross two at the par-5 second.

The duo had finished the regulation 72 holes on 10-under 278, Oosthuizen carding a 3-under 69 and Watson drawing level with a sizzling run of four birdies from the 13th on the way to a 68.

British world No. 3 Lee Westwood birdied four of the last six holes for a 68 to share third place at 8 under with Americans Mickelson (72) and Matt Kuchar (69), and Swede Peter Hanson (73), the overnight leader.

Four-time winner Tiger Woods battled his way to a 74 and a 5-over total of 293, his worst Masters finish as a professional. The American finished level with US Open champion Rory McIlroy (76) of Northern Ireland in a tie for 40th.