Colombian Sebastian Munoz finished with five straight birdies to seize a share of the lead after the first round of the John Deere Classic in Silvis, Illinois on Thursday.
Waterford native Seamus Power is five shots off the pace after a three-under 68 secured with three birdies in his first seven holes plus 15 pars, and level with Scotland's Martin Laird, who mixed five birdies with two bogeys.
75th-ranked Munoz had been down the leaderboard after four birdies and a bogey through 11 holes, but after pars at 12 and 13 the 28-year-old roared into action.
He sank a six foot putt for a three on the par-four 14th, then continued the stunning run home by sinking birdie putts from 11 to 18 feet in his last four holes.
This gave him a superb eight-under 63, putting him level with American Chesson Hadley, who birdied four of his last six in a bogey-free round.
The pair were a shot ahead of a group of three players including another Colombian in Camilo Villegas, plus American Chez Reavie and Hank Lebioda.
"It was a really solid round," Munoz said. "Hit the ball really good all day.I got hot with the putter coming in. I wasn't making a lot on the front nine, so it was nice to see them go in on the back. You know, overall solid golf, make the putts, hit the shots."