Meanwhile, teenage phenom Michelle Wie, playing on a sponsor's exemption, struggled to a 7-over-par 78 despite opening with a birdie on the first hole.
Jason Bohn, runner-up last week at the Oregon Classic, leads a group of eight golfers tied at 4-under-par 67. He is joined there by Kyle Thompson, Kelly Sellers, Jimmy Green, Johnson Wagner, Jason Schultz, Michael Muehr and Todd Demsey.
Warren opened his round on the 10th tee at Hillcrest Country Club and birdied the hole to get his round going. After a string of pars, he birdied the par-5 16th. The 2002 Charity Pro-Am at The Cliffs winner closed out his opening nine with a birdie on No. 18.
Around the turn, Warren kept his strong play going. He rolled in a birdie putt at the first to make it two in a row. The 28-year-old moved to the second and third holes, both par-5s.
He rolled in birdie putts on both holes, for four consecutive birdies, that moved him to minus-6. He parred his final six holes to complete his bogey-free round.
'This is just one of those courses where I feel comfortable,' said Warren. 'This course is major championship caliber and the tournament has a major championship feel. I didn't drive the ball particularly well today but I took advantage of the par-5s. I don't remember the last time I only had 25 putts.'
Wie, who played in a Canadian Tour event in August, became the third female to play in a men's event this year. She joined Annika Sorenstam, who played at the Colonial on the PGA Tour, and Suzy Whaley, who teed it up at the Greater Hartford Open also on the PGA Tour. All three missed the cut at their respective events.
As for Wie, she seems to be facing the same fate. She rolled home a lengthy birdie putt at the first, but came back to bogey the next. She stumbled to three more bogeys on the front side to make the turn at 3 over.
Around the turn, her problems continued. She bogeyed the 11th, then dropped shots on back-to-back holes from the 13th. The 13-year-old closed out her round with a bogey at the last.
'I feel like I've gained some yardage the last few weeks,' said Wie. 'I've been working out a little so I feel stronger. I'll just have to go out and shoot a 64 (Friday). I usually play better in the morning anyway.'
Wilson struggled out of the gate with a bogey at the par-4 11th. However, he came right back to birdie two straight holes. He again birdied back-to-back holes from the 15th and also birdied the 18th to make the turn at minus-4.
On the front nine, Wilson birdied the par-5 second. He then parred out for a share of second place.
'The course completely changed from Tuesday,' said Wilson. 'It is playing extremely tough and getting really fast. The putt on 18 was going 100 miles an hour when it went in the hole.'
Curley also opened on the back nine and he birdied the 10th for a quick start. He later birdied Nos. 15 and 17 to head to the front side at minus-3. On the front nine, Curley drained birdie putts on the third and fifth to move to 5 under. Curley and Warren were the only two golfers to post bogey-free rounds.