San Antonio - Peter Tomasulo's birdie-birdie finish completed a bogey-free five-under par 67 on Thursday and vaulted him into a tie for the lead with Matt Bettencourt at the PGA Tour's Texas Open.
VIDEO: Texas Open Day 1 highlights
The US duo had a one-stroke lead over Ireland's Padraig Harrington and Americans Billy Horschel, Bryce Molder and Harris English, who all finished a windy day at TPC San Antonio on four-under 68.
A group of 10 players on 69 included England's Brian Davis, Australians Nathan Green, Alistair Presnell and Steven Bowditch, as well as Argentina's Andres Romero.
Tomasulo, making just his sixth start of the season on the PGA Tour and trying to regain full playing privileges after battling a rib injury two years ago, played in the last group of the day.
He drained a 10-foot birdie putt at 18 for his share of the lead, and said playing late was an advantage on a day of gusty winds.
"I just played a solid round of golf to go around here with no bogeys," Tomasulo said. "We got a good end of the draw, I think, with the weather calming down late in the day."
Three-time major champion Harrington said "mental fortitude" rather than great ball-striking was the key to his round, played in tougher conditions.
He missed seven greens, but got up-and-down from three bunkers -- including a blast out at the par-five 14th that rolled within a foot of the cup and left him a tap-in for birdie.
A solid performance on the greens was marred by a three-putt from 34 feet at 18, where his first try whizzed past before he missed a four-footer coming back to finish with a bogey.
"That was a pity. Takes the shine off the day," he said. "It wasn't a difficult putt. As I got over it I stood off it once because the wind was gusting from my left, which it shouldn't have been," he said.
The wind from the north also made it feel colder than the temperature of about 50 degrees Fahrenheit (10 Celsius).
"This morning, early on, it was a battle," Harrington said. "Last week back in Ireland it was snowing and I didn't feel this cold."
Even with his lapse at the last, Harrington had a share of the clubhouse lead with Horschel before Bettencourt and then Tomasulo completed their 67s.
Northern Ireland's Rory McIlroy, dislodged from the top of the world rankings by Tiger Woods last month and trying to sharpen up his game before next week's Masters, had four birdies and four bogeys in an even-par 72.
Bettencourt gained his share of the lead despite damaging a wedge when he struck a rock he didn't see when hitting out of rough at the eighth.
"It pretty much destroyed the face of the club," said Bettencourt, who nevertheless used the 52-degree wedge again in the round.
Bettencourt's six birdies included a 21-footer at the 12th, a 405-yard par-four that played into the wind.
The only blemish on his card was a bogey at the par-four fourth, where he missed an eight-footer for par.
Leading first-round scores on Thursday in the $6.2 million US PGA Tour Texas Open (par-72):
67 - Matt Bettencourt, Peter Tomasulo
68 - Padraig Harrington (IRL), Billy Horschel, Bryce Molder, Harris English
- Jason Gore, Brian Davis (ENG), Daniel Summerhays, Jim Furyk, Nathan
Green (AUS), Andres Romero (ARG), Jeff Overton Ben Kohles, Alistair
Presnell (AUS), Steven Bowditch (AUS)
70 - Peter Hanson (SWE),
Martin Laird (SCO), Lee Janzen, William McGirt, Brad Fritsch (CAN),
Brendon de Jonge (ZIM), DJ Trahan, Ian Poulter (ENG), Freddie Jacobson
(SWE), Retief Goosen (RSA), Joe Durant, Matt Every, Shane Lowry (IRL)