Jason Day will need a Monday morning finish to break his 18-month winless drought after failing to finish off Alex Noren in a sudden-death playoff at Torrey Pines before darkness suspended play.
With five extra holes not enough to throw up a winner of the Farmers Insurance Open, the Australian former world No.1 faces a nervous overnight wait.
Day, who won the 2015 event at Torrey Pines in sudden death, and Noren will resume extra holes at 8am PST on Monday (3am AEDT on Tuesday).
"This is something new for me, to be able to go through a playoff and come back the next day," Day said.
"We both played some good golf and I'm looking forward to tomorrow, but I've got to get some rest."
Day was the best performer in regulation, closing the final round with a two-under-par 70 to get in the clubhouse at 10 under before world No.19 and overnight leader Noren (73) and Palmer (72) joined him.
Day and Swede Noren both birdied the first extra hole (the par-5 18th), while American Ryan Palmer made par and was eliminated.
The pair came back to the 18th and again birdied before making consecutive pars on the par-3 16th and par-4 17th.
Day was cruelly denied when his birdie putt from 11 feet stopped inches short of the hole for the win on the 16th.
On the fifth extra hole, 30-year-old Day drained a clutch birdie putt from six feet and Alex Noren two-putted to match him.
"I'll play all day tomorrow if I need to to get the win," said Day, who is chasing his first win on the US Tour since the Players Championship in May 2016.
"This is why we practise. It's a lot of fun to be back in the action."
Noren, who has nine victories on the European Tour, says Day will be a tough obstacle as he chases a maiden win on the US Tour.
"When you play against a guy like (Day), he's going to hit good shots, especially in a playoff," said Noren, who rocketed from world No.102 to No.9 in 2016 courtesy of four wins.
Next best of the Australians was Marc Leishman, who fell to six under after a 73.
Brisbane native Cameron Smith finished at four under courtesy of a closing 72, while Australian Open winner Cameron Davis has plummeted down the leaderboard with an 80 to sit 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 shares 23rd.
For the third day in a row, Woods hit just three of 14 fairways but ground out a respectable score with another incredible short-game scrambling performance.