Little-known American Garrett Willis, ranked 251st in the world and playing on a sponsor invitation, led the Transitions Championship after an opening 65 at Palm Harbour in Florida.
Told two weeks ago there was a place for him in the event, the 36-year-old Nationwide Tour graduate hit back from a third-hole bogey with seven birdies on the par-71 Innisbrook course.
Willis ended the day two strokes in front of Swede Carl Pettersson, defending champion Retief Goosen and home quartet Jim Furyk, Jonathan Byrd, Jeff Maggert and rising star Rickie Fowler.
England's Ross Fisher, playing only his fifth tournament this year, was in a share of second place with two to play, but failed to get up and down from a bunker at the short 17th and finished with a 68.
"I've been playing really well all year," said Willis, whose only PGA Tour victory came in Tucson nine years ago.
"I've made four out of five cuts and I really haven't capitalised on my play. I put myself in position a couple of times and slipped back."
His round included a chip-in three on the 10th which provided the spark for a back nine 30.
Padraig Harrington, back from a St Patrick's Day dinner with President Obama at the White House on Wednesday evening, had an eventful end to his two-under 69.
After opening with 10 successive pars Harrington made a 38-foot putt for eagle on the next and chipped in from 50 feet at the 12th.
A six on the long 13th and another bogey at the 215-yard 17th sent him tumbling down the leaderboard, but he then holed a bunker shot for a closing birdie.
18 March, 2010