American Ryan Moore equalled the course record and his career best with a 10-under 61 in the first round of the Justin Timberlake Shriners Hospitals for Children Open tournament.
Moore had nine birdies, an eagle at the 341-yard par-four 15th hole, and one bogey in a round that gave him a one-shot lead in the PGA Tour event in Las Vegas.
"Just one of those nice days. Got off to a great start -- seven under on the front nine and just kind of cruised the next nine," he said, thanking the lack of wind and perfect temperatures.
"It's one of those days that you just keep putting it in play. You know you're going to have a bunch of pitching wedges, nine-irons, eight-irons into these greens, and a few shorter irons, too."
Brendon de Jonge shot a 62, while Tim Herron and John Huh were one further back on 63 after playing in perfect conditions at the Summerlin course.
Justin Leonard, Chris Kirk and Jonas Blixt were three strokes back on 64.
Moore, who lives in Las Vegas, also shot a 61 this season in the Humana Challenge. He has seven top-10 finishes.
The 29-year-old is aiming to do well this week to try and secure a berth at the Masters next April. He is 36th overall on the money list and the final top 30 will gain starts at Augusta.
Moore's score tied the Summerlin record set 11 years ago by Davis Love, last week's defeated US Ryder Cup skipper.
Chip Beck holds the overall tournament record, shooting a 59 in 1991 at Sunrise Golf Club.