Phil Mickelson birdied the 18th hole Monday morning to finish with a final-round 65 and win the weather-delayed AT&T Pebble Beach Pro-Am.

Mickelson and his playing partner, England's Paul Casey, were the only players still on the course early Sunday evening when play was suspended, with Mickelson holding a three-shot lead at 18-under par. Bad weather accounted for more than three hours of delays on Sunday, leaving them two holes to finish in the morning.

But the wait was worth it for Mickelson and Casey, the third-round leader, who finished in second place.

It was the 44th career win for Mickelson, who has won the tournament on the famed course in Pebble Beach, Calif., five times.

"It's been a very special week," Mickelson, 48, said in post-tournament comments. "This is a special place for me."

Casey also made his birdie putt at 18 to finish his final round at 71 and take sole possession of second place.

Mickelson, riding a wave of momentum, wanted to finish Sunday night despite the dark skies, but Casey objected.

"I thanked Paul this morning for having us finish in the morning because I get sometimes in my own little bubble and don't see the big picture," he said. "The greens were beat up. We had a chance to come out today on fresh greens, better weather and be able to see a lot better. I was very appreciative of that."

This was Mickelson's first win since the WGC Mexico Championship last March, but his first win on U.S. soil since the 2013 Waste Management Phoenix Open.

He finished in second place two weeks ago at the Desert Classic in La Quinta, Calif.

Scott Stallings finished the tournament in third place at 15 under, with Australian Jason Day and South Korean Si Woo Kim tied for fourth at 13-under par.