Perez opened a two-stroke lead over his closest competitor after five rounds in West Palm Beach, Fla.
Kenneth Staton fired a 9-under 63 to move into second place at 25-under. Staton's score matches the course record that was set by Perez in the third round.
Meanwhile, 17-year-old Ty Tryon carded a 2-under 70 to finish at 12-under 348. He stands tied for 50th with 18 holes left in the six-day event.
'At least I've got a chance,' said Tryon, who turned pro this summer before starting his junior year at Dr. Phillips High School in Orlando. 'And I'll take advantage of it, I hope. I don't have any big game plan. Just play golf and make birdies.
'I think I've shown I can hang out here,' he said. 'If I made it here, people can't say much because I've had to go through all three stages. It's not like I was exempt into the second stage or got into the third stage. If I make it, it's more than having one good week.'
The top 35 and ties gain exempt status for the 2002 PGA Tour season. The next 50 after the top 35 earn full status on the Buy.Com Tour for 2002 and the remaining players get conditional status on the developmental circuit.
Perez, winner of the 2000 Buy.Com Ozarks Open, started his day on the 10th hole at the Links Course. He birdied the par-4 10th and posted an eagle at the par-5 11th.
The 25-year-old then birdied the 14th, 16th, 17th and 18th to make the turn in 7-under 29.
Leading comfortably, Perez ran into some trouble with a bogey at the par-4 third, only to make birdie on the par-4 seventh to finish at the top of the leaderboard for the third straight day.
'I'm firing at every pin,' said Perez, who played for Arizona State's national championship team in 1996. 'I feel like I can do anything with the ball, and I haven't felt that in a long time.'
Staton, who missed the cut in both of his only PGA Tour appearances, played an incredible round with nine birdies and no bogeys to climb into second place. Like Perez, he also began his round on the back nine. He parred the 10th before beginning his charge with three birdies over the next four holes.
He added another stretch of three consecutive birdies from the second to put himself in good position to make a run at the top card.
Tommy Armour III rolled in five birdies en route to a bogey-free round of his own. He finished at 22-under 338, one stroke ahead of Ian Leggatt (68), Bob Burns (68) and Pete Jordan (69).
A group of seven players finished tied for seventh at 20-under 340, including Gary Nicklaus. Nicklaus, competing in his 10th Qualifying Tournament, has virtually guaranteed his return to the main circuit.
Danny Ellis (65), Brad Elder (66), John Senden (66), Hidemichi Tanaka (67), Ben Crane (69), and Shaun Micheel (71) joined Nicklaus seven shots off the lead.
Currently, seven players tied at 15-under round out the top 36, including last year's medalist Stephen Allan of Australia.
Full-field scores from the PGA Tour Qualifying Tournament