With heavy rain striking California, wind and hail lashed the iconic Pebble Beach Golf Links, forcing officials to halt play at 10.53am (local time) with leader Paul Casey (15-under-par) and Phil Mickelson (12 under) yet to tee off.
He just couldn't beat the darkness.
Mickelson needs to get through one more day and two more holes if he's to make tournament history and further enhance his World Golf Hall of Fame career.
Even as Mickelson strongly hinted at wanting to finish - at point suggesting they play the 17th and he could scoot ahead to get a ball in play on the 18th so at least he could finish - Casey stood his ground. "But I wanted to try to finish tonight because I'm playing well".
"I get where Paul is coming from", Mickelson said.
"I have pretty good vision", Mickelson said. Casey has a 3-foot par putt remaining on 16 before he and Mickelson make their way to the tee at the par-3 17 and then play the par-5 18 to complete the round.
But the tournament is in Mickelson's hands.
Casey is three shots behind Mickelson in a tie for second place (15 under) with Scott Stallings.
Mickelson birdied four of the first 10 holes.
He also birdied from 6 feet on the second, 7 feet on the 13 and 6 feet on the 14.
There was little good concerning the weather.
After a half inch of rain fell overnight, Sunday's start was delayed more than an hour. Kessler Karain, Patrick Reed's caddie, made a hail angel on the 14 fairway.
It's the first Monday finish since 2009 and one golfer will be chasing their first postponed win at the tournament since 1998 when the final round (54 holes) was played later in the season.
Mickelson also won on a Monday - in August.
Mickelson, 48, is on the verge of closing out his 44th PGA Tour title. He had a biomechanics study done and looked at the kinematic sequence of his swing to pinpoint his strengths and weaknesses.
"It's a tough golf course", Casey said. Casey had great par saves, and then Mickelson took off.
"It's not over yet", Paul Casey said.
"I need to do something special", he said.
Hail quickly covered the greens at the Pebble Beach course. "Phil has put together a spectacular round of golf so far - 6 under, no dropped shots".