Updated

Palm Harbor, FL (SportsNetwork.com) - Brian Davis fired a 6-under 65 in Thursday's first round and the Englishman holds a 1-shot lead over Sean O'Hair and Ricky Barnes at the Valspar Championship.

Davis, a two-time winner on the European Tour, is looking for his first victory on the PGA Tour. Davis last won at the ANZ Championship in 2004, with his other win coming at the Open de Espana in 2000.

"My form has been great lately so to get out there and shoot a low number is always a good thing," said Davis. "It's probably about as easy as you're going to see this course so you got to try and make some birdies today."

O'Hair held the clubhouse lead for a while as a member of the early pairings before he was caught and surpassed by Davis. O'Hair and Barnes both finished the first round on the Copperhead Course at Innisbrook Golf & Spa Resort at 5- under 66.

World No. 3 Henrik Stenson and last week's Puerto Rico Open champion Alex Cejka headline a group of six players tied for fourth at 4-under 67. They are joined there by rookie Justin Thomas, Derek Ernst, Brendon de Jonge and Nicholas Thompson.

Defending champion John Senden carded a 3-over 74 in the first round and he is tied for 114th.

Davis, playing the back nine first on Thursday, had a huge start to his round, which put him in contention right away.

The 40-year-old from England jumped out to a very hot start when he made four birdies in a five-hole stretch from No. 11. After sinking putts of five and nine feet on 11 and 12, Davis poured in an 18-foot putt on 14 and followed that up with a monstrous 49-foot birdie conversion on the par-3 15th.

Following a pair of pars on 16 and 17, Davis converted a 16-foot birdie effort on No. 18 and made the turn at 5-under.

Things began to slow down a bit for Davis as he rattled off four straight pars from No. 1.

Davis then drained back-to-back birdies on five and six, giving him the outright lead at minus-7. That did not last, however, as he tripped to two straight bogeys on seven and eight, dropping Davis back to minus-5.

It appeared as if Davis was going to end the day deadlocked with O'Hair and Barnes, but he chipped in from the rough on the par-4 ninth for birdie to take the outright advantage heading into the second round.

"The wind was down this afternoon and obviously the fairways are soft so it makes them obviously larger," Davis said. "I was able to go at some pins and you know I obviously took advantage of that today."

O'Hair, also playing the back nine first, did not get off to an ideal start with a bogey on 10. He steadied the ship for the rest of his opening nine with birdies on 13, 15 and 18.

O'Hair made it three straight birdies from 18 with two more gains on one and two before tripping to his second bogey on three. O'Hair responded with another gain on four, but gave that shot back with a bogey on five.

The 32-year-old finished strong as he drained birdies on seven and eight to end at minus-5.

Barnes started off well with back-to-back birdies on four and five. He then ran off four straight birdies from No. 9, giving Barnes the outright lead at minus-6 at the time.

Barnes cruised for a bit with four straight pars from 13, but a bogey on 17 dropped him back a shot to 5-under. He finished with a par at the last.

NOTES: Davis has not won on the PGA Tour in 319 events ... O'Hair earned his second career victory at this event back in 2008. He has four wins on the PGA Tour now ... O'Hair's last win was at the 2011 Canadian Open ... Barnes is still seeking his first career win ... Stenson is the top-ranked player in the world at this event with Rory McIlroy and Bubba Watson not playing this week.