UPDATE 1-Golf-American Gay charges five ahead in Mexico

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MEXICO CITY, Feb 23 (Reuters) - American Brian Gay, seeking his maiden PGA Tour title, birdied the last three holes to surge five shots clear in the Mayakoba Classic third round on Saturday.

One stroke off the pace overnight, Gay fired a blistering eight-under-par 62 in ideal scoring conditions on the El Camaleon course at the resort of Playa del Carmen on the Riviera Maya.

That left him at 15-under 195, well ahead of second-placed American Steve Marino who carded a 64.

Overnight leader John Merrick returned a 69 to share third spot at nine under with fellow American Matt Kuchar (64) while PGA Tour veteran Esteban Toledo of Mexico (63) was a further stroke behind in fifth.

"I drove it good all day and just had a lot of chances," Gay told reporters after establishing a 54-hole lead for the second time in his PGA Tour career. "I finally got some (putts) to go in at the finish there."

Asked whether he felt comfortable with a five-shot cushion going into Sunday's final round, he replied: "I've never had a five-shot lead before so I don't know. I'll try to play my game as best I can, just play smart.

Gay, a Walker Cup amateur in 1993 before turning professional the following year, birdied the first two holes before reaching the turn in two-under 33.

He caught fire on the back nine, picking up furthers shots on 10, 13 and 14 before finishing birdie-birdie-birdie.