American trio Keegan Bradley, Ken Duke and Charles Howell III are a shot clear after the opening round of the Valspar Championship, as defending champion Jordan Spieth struggled.
Bradley, Duke and Howell III carded four-under-par 67s to lead the way in Palm Harbor, Florida on Thursday.
Duke and Howell III were faultless following a bogey-free round, while Bradley dropped a shot as he holed five birdies at Innisbrook Resort.
Chesson Hadley is a stroke adrift in fourth via his first-round 68.
Countrymen Charley Hoffman, Greg Yates and Chez Reavie are two under through 18 holes.
Jonas Blixt, Webb Simpson, Martin Kaymer, Danny Lee and Daniel Berger are among 17 players a shot further back.
Meanwhile, world number one Spieth's woes continued after shooting a five-over-par 76 in windy conditions.
Having missed the cut at the Northern Trust Open, then never contending at last week's WGC-Cadillac Championship, Spieth struggled again following six bogeys.
Spieth was in trouble as soon as he teed off on the back nine, bogeying his opening two holes before dropping another three shots at the 13th, 14th and 16th.
"I just didn't hit enough greens," Spieth said. "I had the opportunities on a few holes today and actually there was a lot of holes where I thought if I hit great shots posing and it's 10, 15 yards off on the distance based on the gust of the wind.
"I got off to a poor start and I was behind the eight-ball with gusty wind on a tough golf course. It was a very tough day."