Winning at Riviera was a dream for Homa since he first attended the PGA Tour event as a toddler.

On Sunday, the 30-year-old sealed the Genesis Invitational title, about half an hour after he thought he'd blown it.

In regulation, Homa missed a three-foot birdie putt on the 18th hole for the win – instead joining Finau, whose sparkling 64 was almost enough, at 12-under 272.

On the first play-off hole, Homa appeared to have no chance when his tee shot settled inches from a tree.

He somehow escaped to extend the playoff and won it on the next hole when Finau failed to save par from a bunker on the par-3 14th.

As much of a heartbreak as it was for Finau – his 10th runner-up finish worldwide since his lone victory in the Puerto Rico Open five years ago – the emotion was too much for Homa.

"I've been watching this tournament my whole life," Homa said, choking back tears.

"Wow. I didn't think it would be like this ... The city of champions – Dodgers, Lakers, me now.

"It's a weird feeling."

Homa not only closed with a five-under 66, he played the final 26 holes without a bogey.

"I've been watching this tournament my whole life. Wow. I didn't think it would be like this ... The city of champions – Dodgers, Lakers, me now. It's a weird feeling." – Max Homa

The victory allowed Homa to crack the top 50 in the world for the first time, making him eligible for the World Golf Championship next week and getting him back to the Masters.

Sam Burns, who had led from the opening round, ran into a string of bogeys on the back nine and his 69 left him one shot shy of the playoff.

Smith made a final-round charge and was 10-under after 13 holes but bogeys on 14 and 16 ended his hopes, signing for a four-under 67 to take fourth.

"I struck it probably the best I've struck it in a very long time, three, four years probably. It's nice to get back in that groove," Smith said.

"Left a few iffy putts there on the back nine that could have gone in, but hit really good shots.

"It was just Riviera out there on the back nine, just punishing you unnecessarily sometimes, but that's golf."

A triple-bogey on the par-4 12th ruined any dreams Matt Jones had of contending with the Sydneysider's 70 leaving him at six-under and a tie to eighth, in a group with World No.1 Dustin Johnson (72).

Of the other Aussies playing the weekend, a 68 lifted Marc Leishman to a share of 32nd, 11 shots off the winner, Adam Scott closed out his title defence with a 66 to rocket his way to even par while Cameron Davis was a shot further back courtesy of a 68.