Jason Day says he felt his world No.1 form returning during his drought-breaking US PGA Tour victory at Torrey Pines.
The 30-year-old Australian finished off Sweden's Alex Noren on the sixth play-off hole at the Farmers Insurance Open to claim his first win worldwide since the 2016 Players Championship.
When darkness suspended the play-off on Sunday, officials scheduled the first Monday finish at the famed San Diego course since Tiger Woods triumphed in an 18-hole play-off at the 2008 US Open.
Returning to the par-5 18th, Day hit a sublime wedge and tapped in for birdie to defeat world No.19 Noren, who went for the green in two but rinsed his second shot en route to a bogey.
After losing his 47-week stranglehold on the world No.1 ranking to Dustin Johnson last February, Queensland native Day says his 11th PGA Tour victory marks the return of his world-beating 2015 form.
He will rise four places from No.14 to return to the top 10 after the win.
"It felt like it was coming back, I think more the mental side of my game; the drive to get back to No.1 and the desire to win was definitely there this week," Day told AAP.
In 2015, Day won at Torrey Pines in play-off before recording another four wins on the US Tour and rocketing to a maiden stint as world No.1.
"The hunger to win every event is what I had as the No.1 player and last year, I lost that a little, but this year is a totally different feeling and to have that again is really pleasing," said Day.
Winless at the majors since breaking through at the 2015 US PGA Championship, Day says he is confident of bagging a second big one.
"Being able to get off to a great start this year makes me more hungry and sets up major championships because I'm really focused on the major championships every year," said Day.
Day was the best performer in regulation, closing the final round with a 70 to get in the clubhouse at 10-under before world No.19 and 54-hole leader Noren (73) and Ryan Palmer (72) joined him in the play-off.
Next best of the Australians was Marc Leishman, who fell to six-under after a 73 but salvaged a tie for eighth.
Brisbane native Cameron Smith (72) was 20th at four-under, while Australian Open winner Cameron Davis (80) plummeted down the leaderboard to share 58th at three-over.
Tiger Woods made an even-par 72 to finish at three-under in his US PGA Tour comeback and the 14-time major winner tied for 23rd.