Piercy followed his tournament-record 54-hole score with a wince-inducing 76 to tie for fourth on Sunday, four strokes back.

Finau finished at 17-under. South Korea's Sungjae Im (68) and Emiliano Grillo (71) of Argentina tied for second while James Hahn surged up the board with a 65 to match Piercy and Tom Hoge (70) at 13-under.

Cam Davis (69) was the best-placed Australian in joint-16th at seven-under.

Cameron Percy (72) finished two shots further back, with Aaron Baddeley (73) one-under, Jason Day (72) two-over and Greg Chalmers (72) four-over.

"I was playing great and every time I looked up, it seemed like I was four, five shots back really all day. Once I took control of the golf tournament, it was a whole different mindset trying to seal the deal." - Tony Finau.

Piercy bogeyed four of six holes before a triple-bogey implosion on 14, allowing Finau – playing in the preceding trio – to take over for good on his way to his third career Tour victory.

"I was playing great and every time I looked up, it seemed like I was four, five shots back really all day," Finau said.

"I really got things going in the middle of our back nine.

"Once I took control of the golf tournament, it was a whole different mindset trying to seal the deal."

The surest sign this was Finau's day came on No.17. His tee shot clanged off the side of the grandstand, ricocheted back onto the green and rolled into the rough – just a few feet from the water. He landed the perfect chip within a foot of the hole to make a par three, then smiled slightly as he playfully clamped his hand on his chest as if to pretend the sequence gave him heart trouble.

RELATED: Inside Finau's winning bag

On the daunting par-5 18th, Finau found the water off the tee to face one final challenge. After the penalty stroke, his recovery shots were spot on. With Piercy looking on from the fairway, Finau made a three-footer for bogey to seal it. He pumped his fist several times, took off his cap and walked off to embrace his family.

Finau, who tied for third at the 3M Open in 2020, jumped from 30th to 17th in the FedExCup race. He entered the week ranked 17th in the world.

Piercy shared the first-round lead with Im on Thursday. He was at 20-under after six holes, but in trouble less than an hour later. After posting only three bogeys on his first 61 holes, he went over par on seven of his last 11.