He finished the tournament at 17 under, three ahead of Charlie Wi, who had led for three days but is still yet to collect a win in his 18th season on the Tour.

Playing imperiously, and picking up five strokes in the first six holes, Mickelson's victory was made sweeter by the new World No. 11's early season struggles.

"I felt my game was there, but coming out the first couple weeks, I posted some horrendous scores and started to question it," said the 41 year-old.

"To be able to play the way I did the last 18 holes really means a lot."

Only one year his junior, Wi's career starkly contrasts the four-time major winner, and his failure to convert a three-shot lead is the third week in a row where a player chasing their maiden Tour trophy has thrown away a commanding advantage.

Wi's challenge was immediately under threat as he double-bogeyed the first and dropped further shots on the fifth and sixth.

But three consecutive birdies over the last holes were not enough to clinch the title and he finished a disappointing day on even par, at 15 under, two shots ahead of Ricky Barnes.

Mickelson's Sunday playing partner, Tiger Woods, looked ideally placed to strike after the third round but could only limp home with a three-over 75 to finish on eight under, tied for 15th.