San Martin, CA ( - Jeff Overton fired a 7-under 64 on Thursday to grab a 1-stroke lead at the end of the first round of the Open.

Brian Harman shot a 6-under 65 during his opening round at CordeValle Golf Club to sit in second place, while Kyle Stanley is alone in third following his 5-under 66.

"This place is awesome," Overton said about CordeValle. "It's one of the better golf courses we play all year. Not that any of them are bad, but it's really a neat place and it's really cool."

Michael Putnam, who recently won the Tour's regular season money title to earn his PGA Tour card for this season, carded a 4-under 67 to sit in a share of fourth place. He is joined by Jason Kokrak, J.J. Henry, Charlie Wi, Jim Herman and Brooks Koepka.

This event is the first of the PGA Tour's new fall-to-late-summer 2013-14 schedule, which includes an early opportunity for players to earn FedExCup points.

Overton went out with one of the last groups of the morning wave and opened his round with seven straight pars before moving into red numbers with a 25- foot birdie putt at the eighth. He followed that with a 21-foot eagle putt at the ninth to make the turn at 3-under.

After kicking in a short birdie at the 12th, Overton made it two in a row by holing out from just off the green at the 13th to move to 5-under.

He added another long birdie putt from 30 feet at the 17th, and then hit his second shot at the last to within two feet and converted that short birdie to head into the clubhouse with the lead at 7-under.

"As far as ball-striking goes, it was as good as I've hit it all year," Overton said about his performance. "It was pretty fun."

No one was able to get closer than two strokes of Overton's lead until Harman posted the best score of the afternoon wave.

Harman started on the 10th tee and parred his first two holes before recording birdies at the 12th and 14th around a 2-putt bogey at the 13th.

He then capped a streak of three straight lengthy birdie putts around the turn with a 21-foot effort at the first to move to 4-under.

A bogey at the second halted his momentum, but he bounced back with gains at the fifth, eighth and ninth to move within a stroke of the lead.

Stanley traded a bogey at the first with a birdie at the fourth to make the turn at even par. He then used a strong closing stretch that included three birdies around a 33-foot eagle putt at the 15th over his final seven holes to reach 5-under.

NOTES: Overton finished in eighth place at this event in 2012 ... This is the fifth time Overton has been the leader/co-leader after the first round on the PGA Tour ... The winner of this event will earn an invitation to the Masters for the first time ... Since moving to CordeValle in 2010, the only first- round leader to hang on for the win was Rocco Mediate in 2010 ... Defending champion Jonas Blixt carded a 2-under 69 during his first round to sit in a tie for 19th place.