Paul Lawrie, the 1999 British Open champion, finished two shots off the lead at 3-under-par 68. He was joined by Glen Hnatiuk, Niclas Fasth, Rory Sabbatini, Patrick Sheehan, Hal Sutton and Tom Gillis in a tie for fourth.
With the U.S. Open right around the corner, several players are preparing at a saturated TPC at Avenel. However, Gamez can only wait as an alternate next week at Olympia Fields.
Gamez played the back side first and opened quickly with a birdie at the par-4 10th. He caught fire three holes later with the first of three consecutive birdies starting at the par-5 13th to move to four-under.
The 34-year-old faltered on his second nine with a bogey at the par-4 fourth. He responded with a birdie at the very next hole and climbed to minus-5 with a birdie at the fifth.
Gamez reached 6-under-par with a birdie at the seventh but stumbled again with a bogey at the eighth. At the par-3 ninth, Gamez picked up his seventh birdie of the day to take the lead after the opening round.
'I really thought the course played pretty easy,' said Gamez. 'It played long, but the greens are soft. You can fly the ball right at the hole.'
Gamez, who has played well under a hectic schedule over the last few weeks that includes a tie for second at the Wachovia Championship, had trouble making his early tee time but nevertheless was ready to play.
'It was hard to get out of bed this morning,' said Gamez, a two-time winner on the PGA Tour. 'But when I got to the tee, I got fired up. I love this golf course.'
Begay got things started with a birdie at the par-4 first. He then added a birdie at the par-5 sixth and picked up another at the par-5 13th. At the par-4 15th, Begay hit his second shot within a foot of the hole and tapped in for his fourth birdie of the day.
'The conditions are extremely unpredictable,' said Begay. 'With the swirling wind and trees, it really makes club selection very confusing.'
Charles Howell III, Jay Don Blake, Joe Durant, Darron Stiles, Steven Alker, Esteban Toledo, John Huston, Joel Edwards, Garrett Willis, Hidemichi Tanaka, Alex Cejka and Troy Matteson finished tied for 11th at 2-under-par 69.
Davis Love III was one shot further back at in a group at 1-under-par 70.
Defending champion Bob Estes collected two birdies to go along with three bogeys for a round of 1-over-par 72.
Phil Mickelson struggled throughout his round with two birdies, two bogeys and a pair of double-bogeys. Mickelson finished nine shots off the lead in a group at 4-over-par 75.