Austin - Two-time Masters champion Bubba Watson denied Justin Thomas the world number one ranking by defeating his US compatriot 3&2 in a semi-final on Sunday at the WGC Match-Play Championship.
Watson advanced to Sunday afternoon's final against American Kevin Kisner, who met in the other semi-final at Austin Country Club.
"I didn't really make any mistakes," Watson said. "And then I made some putts early. You have a chance to get the lead. I played solid and he didn't make any putts."
Thomas, who won his first major at last year's PGA Championship, was chasing his fifth title in eight months and would have overtaken American Dustin Johnson atop Monday's world rankings had he reached the final. Johnson crashed out in the group stage.
Watson, the 2012 and 2014 Masters winner, seeks his 11th PGA crown just five weeks after a victory at Riviera and with this year's Masters set to open April 5 at Augusta National.
"It's just the mental focus, trying to make sure I'm in every shot, committed to every shot," Watson said of the secret to his week's success. "You can make a birdie run or come back or take a big lead."
Watson left his approach seven feet from the cup on the first hole then birdied to grab a quick lead on Thomas, going 2-up with a nine-foot birdie at the fifth.
Watson sank a 25-foot birdie putt to win the par-5 sixth but Thomas answered with a 10-foot birdie to claim the par-3 seventh and a 23-foot birdie putt to take the ninth and make the turn only 1-down.
After Watson sank a 10-foot birdie putt to win the 10th and go 2-up, Thomas found water with his second shot at the par-5 12th and made bogey to fall 3-down.
The end came for Thomas at 16. Watson blasted out of a bunker three feet from the cup. Thomas, beyond the green just off a cart path, blasted 22 feet past the hole before sinking the birdie putt. Watson followed by tapping his birdie in behind him to clinch victory.
Kisner chases the biggest title of his career, having won PGA crowns at Colonial last year and Sea Island in 2015.
Noren missed a six-foot par putt to drop the opening hole to Kisner, then locked into a putting duel where both birdied four holes in a row - Kisner halving holes from 22 and 28 feet in the run - until Noren sank a 17-foot putt to birdie the par-3 seventh and square the match.
When Kisner missed a 4 1/2-foot par putt at eight, Noren took his first lead 1 up. But Kisner drew a huge roar from the crowd at 12 by sinking a 51 1/2-foot eagle putt to level the match again.
Both men parred the next six holes to force a playoff that began at 12. Noren botched an eagle attempt and missed a 10-foot birdie try, setting the stage for Kisner's winning putt.