Robert Streb rode a blistering start to an 11-under par 61 and the first-round lead on Thursday in the CJ Cup at the Summit Club in Las Vegas, Nevada.
The American, a two-time winner on the US PGA Tour, matched the best start to a US tour event when he opened with five birdies and an eagle to reach seven-under through six holes.
A bogey at the 11th was just a hiccup as Streb rebounded with birdies at the 12th, 13th and 14th before adding two more birdies at 16 and 18.
"It was going really well," Streb said of his opening burst, launched with a seven-foot birdie at the first followed by a six-foot birdie at the second.
He drained a 12-foot eagle putt at the third, and then rolled in a 17-footer at the fourth and a three-foot birdie at the fifth, capping the run with a two-putt birdie at the par-five sixth.
"Obviously (I) hit a few close, and the putts were going in," Streb said.
"Slowed down a little I guess in the middle, but it was a really, really good round."
Afternoon starters made gains, but none could surpass Streb, who had a one-shot lead over fellow American Keith Mitchell.
Mitchell, who missed the cut in his last two starts, fired 10 birdies — picking up a stroke at each of the four par-fives — as he matched his career-best with a 10-under par 62.
American Harry Higgs was alone in third, posting the last of his nine birdies at the par-five 18th for an eight-under par 64. -AFP