Jason Day birdied the sixth extra play-off hole to see off Alex Noren and secure a first victory in 20 months at the Farmers Insurance Open.
Five sudden-death holes couldn't separate the players before darkness saw play suspended late on Sunday, leaving the duo returning to play a fifth day at Torrey Pines.
Beginning at the par-five 18th, Noren found the first cut off the tee but saw his approach come up short and spin back into the water hazard, as Day drove right and elected to lay up from the rough.
Noren pitched on to the green with his fourth shot and two-putted for bogey, as Day fired his approach tight into the flag and nudged in the two-foot birdie putt for victory.
"It has been a long time coming," said Day, who battled a back injury at the start of the week and missed the pre-tournament Pro-Am. "I know that last year wasn't the greatest season and I had some stuff off the course that was a little distracting.
"It's special because I worked very hard in the off-season to try and get back in to this position and I didn't realise I had a chance this week.
"My goal has always been to try and get back to world No 1 and this is a step in the right direction."
Victory is Day's 11th on the PGA Tour and first worldwide since the success since the 2016 Players Championship, while Alex Noren ended joint-second alongside Ryan Palmer - who was eliminated at the first extra hole on Sunday.