03/12/2015 03:57 EDT | Updated 05/12/2015 05:59 EDT

Sean O'Hair headed in the right direction, opens with 5-under 66 at Innisbrook

PALM HARBOR, Fla. - Sean O'Hair believes his game is going in the right direction, and a 5-under 66 gave him more evidence Thursday in the Valspar Championship.

O'Hair made eight birdies — four of them on par 3s — in pleasant conditions for his lowest opening round since Las Vegas in October 2013. He had a one-shot lead over Henrik Stenson, Justin Thomas and Derek Ernst among the early starters.

Even in relatively benign weather, the Copperhead course at Innisbrook held its own. Only 18 players from the early wave shot in the 60s, and the course was playing about a stroke over par.

Stenson, at No. 3 the highest-ranked player in the field, is playing for the first time and likes what he sees. He just didn't like the swing he had on the range, though he hit enough good iron shots early on to get him by. Stenson hit wedge into the par-4 ninth for a final birdie in a bogey-free day.

Thomas opened with all pars on the back nine, and then took bogey on the par-5 first hole when he had mud on his ball and pulled it into a bunker. But he bounced back with five birdies on his last eight holes for a solid start. Thomas, a 21-year-old rookie, closed with three straight birdies.

Nick Taylor of Abbotsford, B.C., opened with a 70.

Stenson played with Adam Scott, who made four straight bogeys on his back nine that ruined a good round. He had a birdie on the final hole for a 71. Also in the group was Jordan Spieth, slowed by a double bogey in his round of 70.

"Fell asleep out there for about 30 minutes," Scott said.

O'Hair won at Innisbrook in 2008, though he has fallen on lean times. He has had to earn his card at the Tour Finals each of the last two years, and he withdrew from his first event this season with a neck injury.

This is already his 10th event.

"The last two years have been disappointing for me," O'Hair said. "I lost really everything. I lost my ball-striking and kind of lost my mind, lost confidence as far as how I play the game because I like to hit a lot of different shots and I got very swing-oriented."

A poor swing and poor results were starting to weigh on him. At least he found his game in the four-event series at the end of the year that enabled him to keep his card. Still, he conceded he was feeling stressed.

"I've been losing my job the last few years. Wouldn't you be stressed?" said O'Hair, with a laugh. "I know I'm headed in the right direction. It's been a long time since I felt that way. You know when you're on the right road. When you're lost, you might get good results and know in the back of your mind that it's smoke and mirrors. This isn't just a flash in the pan. I've been seeing a lot of good things start to come around."

So is Ernst, who hasn't won since Quail Hollow as a rookie two years ago. That remains his only top 10 on the PGA Tour.

Kevin Streelman, who won at Innisbrook two years ago, was in a large group at 68. Ernie Els and Lucas Glover were among those at 69.

John Daly opened with a double bogey when he three-putted from 5 feet. He later four-putted for triple bogey on the 14th hole. A birdie on the final hole gave him an 81, but there was a sliver of good news at the end of his long day. He wasn't selected for drug testing.

"No, that's tomorrow," said Daly, with a grin.

He said on his SiriusXM radio show Tuesday that night the PGA Tour didn't have random testing because he has been picked at Innisbrook the last six years.

DIVOTS: Course owners said Thursday the Copperhead course will go through an extensive restoration this summer, primarily to replace the grass in the fairways and rough, to rebuild the greens and reshape some of the bunkers to the original Larry Packard design. "Hopefully, they don't mess around with the design too much because I think we've got a really good golf course here," Adam Scott said. ... Padraig Harrington, in his first start since winning the Honda Classic, opened with a 76.