Seeking a long-awaited second Tour victory, World No.12 Finau led by two shots with just two holes to play at TPC Scottsdale.

But 2012 US Open champion Simpson (69) made clutch birdies on each of the last two holes to catch overnight leader Finau (70) at 17-under 267, then birdied the first extra hole with a 10-foot putt to secure his sixth US Tour title.

Finau has played on American Ryder Cup and Presidents teams but has not been able to win since the 2016 Puerto Rico Open almost four years ago.

He also lost a playoff to Xander Schauffele in November 2018 in China at the WGC-HSBC Champions.

"It's hard. He is a great friend," Simpson said. "Our wives are friends and he's one of the best guys on Tour. So it is a bit tough."

RIGHT: Simpson defeated Finau at the first extra hole. PHOTO: Christian Petersen/Getty Images.

Finau made par at the last two holes in regulation where Simpson charged, then missed his 18-foot birdie try at the first playoff hole.

He was philosophical in defeat.

"If you are going to get beat, that's how it should happen," Finau said.

"I definitely didn't give him the tournament. Unfortunately, it's how the cookie crumbles.

"I love Webb. I think the camaraderie that I have with him as being one of my best friends out here, it would have been hard for either one of us to take this victory from each other."

Simpson improved his poor playoff record to 2-6, three years after falling to Hideki Matsuyama in extra holes at TPC Scottsdale.

Fourth-ranked Justin Thomas (65) tied for third at 14-under, along with Bubba Watson (66) and Nate Lashley (68).

Aaron Baddeley, the lone Australian to make the cut, closed with a three-under 68 to move up 11 places and a share of 40th.