Mickelson went from a four-shot lead at the start of the final round to a two-shot deficit with three holes to play.
Mickelson closed with a 1-over 72 to become only the fourth player to win in consecutive years at Riviera. It might have been three in a row if not for his sloppy bogey on the 18th hole two years ago, when he wound up losing in a playoff.
Ill take a lot out of this, Mickelson said. To make par on 18 when two years ago I didnt, that meant a lot to me.
Stricker closed with a 67 and was on his way to the range to get ready for a playoff when he saw Mickelson leave himself a tough par putt on the final hole, and stopped when he heard the cheer.
He had his chances. Stricker missed a 12-foot birdie putt on the par-5 17th that would have given him a three-shot lead at the time, then missed a 12-footer for par on the 18th.
It was the second time on the West Coast that Stricker had a chance to win. He had a three-shot lead at the Bob Hope Chrysler Classic until he was blown away by the raging desert wind, closing with a 77.
Its just a little disappointing when you dont finish it off, or have the opportunity to finish it off, he said. And I didnt.
But the real heartache belonged to Fred Couples.
A two-time winner at Riviera, his favorite golf course west of Augusta National, the 49-year-old had a chance for one last victory in his final full season on the PGA Tour. Couples was one shot behind when he fanned his approach to the 18th green and watched in disgust as it struck a eucalyptus tree. He finished with a bogey for a 69 to tie for third with K.J. Choi (69) and Andres Romero (70).
Couples learned earlier in the week that his estranged wife, Thais Baker, died Tuesday of breast cancer. They never divorced after splitting up nearly four years ago, and Couples said he is not welcome in their home in Santa Barbara.
She was a nice person, he said. She did everything she could to make it another month.
Mickelson finished at 15-under 269 and won for the 35th time in his career. It was the first time since the 2005 PGA Championship that he won a tournament without breaking par in the final round.
Lefty won for the 17th time on the West Coast, and it could not have come at a better time. He had failed to break the top 20 in his first three starts, missing the cut in Phoenix and making it on the number at Pebble Beach.
And while a victory should take care of any talk about a slump, this was one of his wildest wins yet'63-72-62-72.
Mickelson had never lost a PGA Tour event when leading by more than four shots going into the final round, but what appeared to be his biggest collapse turned into a stunning recovery.
First, he began hitting 3-wood off the tee to gain some confidence. And when he unloaded a tee shot down the 15th fairway, the comeback was under way.
Mickelson led by as many as five shots when he opened with an eagle for the third straight day, although it might have been the first sign of a struggle to come. The hole was in the middle toward the back, easy to access, yet Mickelson had to make a 40-foot putt.
The next two holes were more obvious.
He had trouble with the sticky kikuya grass, muffing a chip on the second hole to make bogey, and with his driver, hooking his tee shot on the third so badly that it struck a eucalyptus tree 170 yards off the tee, leading to another bogey.
And yet, no one in the final group took advantage.
Couples opened with an eagle from 3 feet, and his wedge on the third hole checked up 3 feet from the cup. He made birdie, but it was a nervous stroke, and he badly missed a 3-foot par putt on the fourth, a 8-foot birdie on the sixth and a 6-foot birdie on the seventh.
Romero went at every flag, but couldnt make a putt unless it was for par ' or bogey. The 27-year-old Argentine twice made stunning par saves, on the fifth and eighth, to stay in the hunt. But he hooked his tee shot out of bounds on the 12th, ending his hopes.
Stricker made three birdies in a four-hole stretch around the turn, with a 6-footer at No. 12 giving him the lead for the first time all week. He never had another good look at birdie until the 17th, and that was the one he badly needed to make.
I didnt know what the lead was at the time, but I knew I had the lead, he said.