PEBBLE BEACH, Calif. — Phil Mickelson put himself on the brink of a fifth victory in the AT&T Pebble Beach pro-am by turning a three-shot deficit into a three-shot lead when a wild day of weather kept him from finishing Sunday.

Mickelson was bogey-free with six birdies, and he made his big run starting with a 9-iron to a foot behind the cup on the par-4 ninth. That was start of a five-hole stretch when Mickelson made three birdies and Paul Casey had two bogeys.

About the only thing that didn’t go Mickelson’s way was the timing.

The final round started an hour late because of rain, and then it was delayed two more hours when sunshine gave way to a hail storm in a matter of minutes, covering the putting greens in a sheet of white.

Mickelson was at 18-under par through 16 holes. Casey had a 3-foot par putt on the same hole when Mickelson tried to lobby for them to finish, even in the dark.

“I can see fine,” Mickelson told a rules official. “I don’t want to put Paul in a bad spot.”

Casey was at 15 under, tied with Scott Stallings, who closed with a 66. Along with an outside chance at forcing a playoff, finishing alone in second instead of a tie is a difference of $152,000, along with world ranking points and FedEx Cup points. Casey and FedEx executive Don Colleran had a one-shot lead in the pro-am.

“I don’t see how we can finish,” Casey said as they walked up the 16th fairway. “We can’t finish two holes in six minutes. I’d like to.”

Mickelson was standing on the 17th tee when he heard the horn sound to stop play, and he shook his head.