American John Merrick rolled in a 50-foot birdie putt on his final hole to grab a one-stroke lead in the Mayakoba Classic first round on Thursday.

The 25-year-old shrugged off gusting winds and occasional rain to shoot a flawless six-under-par 64 on the El Camaleon course at the resort of Playa del Carmen on the Riviera Maya.

Former Masters champion Larry Mize also signed off with a birdie, an opening 65 leaving him joint second with fellow American Robert Damron, Briton Kenneth Ferrie and PGA Tour rookie David Lutterus of Australia.

Merrick, playing his fifth Tour event of the year, felt he could have gone lower despite the testing conditions.

"I hit a lot of greens and a lot of good shots and even missed some more potential birdies today," said the Californian.

"It was just a great day, one of those days where everything kind of went your way. It was fun.

"I played here last year and actually shot 64 in the opening round, so it's kind of funny how it worked out today," added Merrick after piling up six birdies.

"It was very windy out there. With some shots, you needed two extra clubs to try to flight it down under the wind. It was tough."

Double major winner John Daly opened with a 66 and former world number one Greg Norman fired 70.

American Fred Funk, who became the fifth oldest winner in PGA Tour history with a playoff victory here over Argentina's Jose Coceres last year, launched his title defence with a 73.

With the game's leading 64 players competing in this week's WGC-Accenture Match Play Championship at Dove Mountain's Gallery Golf Club in Marana, Arizona, Funk and company have a freer hand.