Gay closed with a 9-under 63 on PGA West’s Arnold Palmer Private Course to match Howell and Swedish rookie David Lingmerth at 25-under 263.

Howell shot a 64, and Lingmerth had a 62. Stallings, five strokes ahead entering the round, bogeyed the final hole for a 70 to miss the playoff by a stroke.

The 41-year-old Gay began the round six strokes behind Stallings.

“The thoughts were, ‘Just be aggressive, shoot as low as you can,’” Gay said. “I knew Scott was five ahead. Even with a great round, a really low round, it would be tough to catch him, if at all. I played great on the front, just tried to stay aggressive and shoot low.”

Gay and Howell opened the playoff with birdies on the par-5 18th, and Lingmerth dropped out with a bogey after hitting his approach into the left-side water.

Gay won on the par-4 10th, hitting a perfect drive and putting his 9-iron second shot in good position below the hole. Howell drove into the right rough, hit his second into the back bunker, blasted out to 15 feet and two-putted for bogey.

“I’m still in a little bit of shock,” Gay said. “It kind of happened so fast there at the end the way things went down. Last year was a struggle. It was a long year, a lot of work. I just wanted to come out this year kind of refocused, recharged, and believing in myself.”

Howell tied for second a week after opening the season with a third-place tie in Hawaii in the Sony Open. He won the last of his two tour titles in 2007.

“Anybody that says that that golf is fun or whatever, has really not done it for a living,” Howell said. “I would never characterize this as fun. It’s different than that. It’s awfully challenging mentally and the chances to win are what we want.”

After birdieing nine of the first 13 holes, Gay finished regulation with five straight pars. On the 18th, he missed the green to the right and failed to hole an 8-foot birdie try.

“I felt like I gave one back with a par on 18 there,” Gay said. “Was fortunate enough to feel like I had a second chance with two guys left that didn’t birdie the hole. Kind of a second chance, if you will. I was happy to be in the playoff at that point.”

Given that second chance, he outlasted Howell for his fourth PGA Tour title. He won the Verizon Heritage and St. Jude Classic in 2009 and the Mayakoba Golf Classic in 2008.

Playing in the second-to-last group, Howell had a chance to pull ahead on the final hole of regulation, but left his approach about 85 feet short and three-putted for par. His 5-foot birdie try made a sharp left turn inches from hole.

“Quite honestly, going into the day, I didn’t really think that anybody had a chance apart from Scott,” Howell said. “He’s won before, he hits it long enough to take advantage of the par 5s. At 22 under, I figured if he shoots 6, 7 under, he’s really not catchable. So, then to have a chance there in regulation, that’s where I really would like that one back, that three-putt there. But it happens and once you get a playoff, anything can happen.”

Stallings hit a 315-yard drive on the 18th to set up a 6-iron approach from 220 yards. The ball landed in the left rough, bounced into rocks and finished in the water. After a penalty drop, he chipped to 10 feet and missed his par try.

“I felt great. There wasn’t any nerves or anything like that going into it,” Stallings said. “Just hit a bad shot. Same thing that happened on 14. Felt like I made a good swing, just ball came off a little right and got a bad kick and went in the water.

“Coming down the stretch on the 72nd hole, you can’t make mistakes like that. And it stinks, but it’s something that I’ll definitely learn from.”

The two-time tour winner saved par on the par-5 14th after hitting his into the All-American Canal on the right side, but dropped a stroke on the par-4 16th after his 4-iron tee shot went farther than he expected and ended up in the lip of a fairway bunker.

“You’re going to have your good days and your bad days, but if you live and die with every shot out there, your career is not going to last very long out there,” Stallings said.

Making his second career PGA Tour start, Lingmerth hit his 4-iron approach way left into the water in the playoff. He had an awkward stance on the shot with the ball above his feet.

“I didn’t feel that comfortable over it, obviously,” Lingmerth said. “I just hit a bad shot. I wish I could have it back. … I was fortunate to have a chance here, and I’m sure I’ll learn from it looking forward to the next opportunity.”

Phil Mickelson had a 66 to tie for 37th at 17 under in his season debut. He was making his start since the HSBC Champions in early November in China.

“I was rusty starting the year,” Mickelson said. “I had a great four days here where I can work on my game with perfect weather and wonderful golf courses, where I could build some momentum. Heading into San Diego, I feel a lot more confident in my game. I feel like I’m starting to play well, hit some putts on line.”

DIVOTS: James Hahn eagled the last for a 62 to tie for fourth with Stallings. … Russell Henley, the Sony Open winner last week in his first start as a PGA Tour member, tied for 56th at 15 under after a 69. … FedEx Cup champion Brandt Snedeker shot a 67 to tie for 23rd at 19 under. He was the highest-ranked player in the field at No. 8.