The 41-year-old finished at 17-under for a two stroke tournament victory over third round leader Charlie Wi (72) of South Korea.
Mickelson was in great touch and his round made the effort by his playing partner and long-time rival Tiger Woods (75) look very ordinary.
“It feels amazing,” Mickelson said. “Hopefully this is one of a few I will win this year because I am starting to feel pretty good.”
Mickelson got off to a great start with an eagle and three birdies in his first six holes and with the putter running hot twice saved crucial pars by sinking long putts on the back nine.
As seems to have become his lot of late, Woods was well in contention after three rounds but didn’t have the inner wherewithal to keep it going when it really mattered.
The golfing media were starting to get excited there but once again had to pack away the “He’s back!” stories for another day.
“It is frustrating,” Woods said. “I had a chance. All I needed was to get off to a good start today and I didn’t do that.”
Another who came into contention down the final stretch was Australia’s Aaron Baddeley who finished with a five-under 67 to be outright fourth a stroke behind third placegetter Ricky Barnes (67).
It was a timely show of form by Baddeley who this week will be defending his title at the Northern Trust Open at the Riviera Country Club, Pacific Palisades, California.