Los Angeles - Peter Uihlein fired a 63 to grab the lead on Thursday in the first-round at the PGA Tour's Shriners for Children Open, where Jordan Spieth launched his season with a solid performance.
The 29-year old American Uihlein birdied his final hole - the par five No 9 - for his ninth birdie of the round and an eight under score before play was halted because of darkness at TPC Summerlin in Las Vegas, Nevada.
Seth Reeves was alone in second at seven-under 64, finishing just before the horn sounded to end play for the day.
Harold Varner and Robert Streb both shot 65s to finish two strokes back of Uihlein.
Three-time major winner Spieth was also in contention after firing a five-under 66. He was tied with six others for a share of fifth.
"It's getting close to where I feel like I can just kind of point, aim, shoot, which is where I want to be," said Spieth, whose last win came at the 2017 British Open.
"Something like today will work into being the norm for me going forward. I know how not to have it get so off again," Spieth said.
"If I shoot three more rounds like today it's probably good enough (to win)."
A total of 20 golfers will complete their opening round on Friday morning.
Uihlein began his back nine with four straight birdies, beginning at the par-four first hole.
He finished with six birdies on the back and three on the front nine. His only blemish came on the par-four seventh when he made bogey.
Spieth, who is playing in his first event of the 2018-19 season, put on an impressive display also closing out his opening round with a birdie on No. 9 by rolling in a 27-foot putt.
Spieth, 25, is hoping to bounce back from a winless season in 2017-18 and a failure to reach the Tour Championship for the first time in his career.
He also birdied the par-four fourth by landing his approach to within six feet of the cup, and on the par-three 17th his tee shot stopped 10 feet from the pin for a one-putt birdie.
"Really solid inside of ten feet today, even with somewhat trickier ones as the wind picked up," he said.
"That's where rounds go to five under instead of two under. I was certainly able to save a couple coming in.
"I've been hitting some pretty good putts for the last six or seven tournaments. I saw some go in at the Ryder Cup under the biggest pressure, so today kind of felt, at least heart rate-wise, like a little bit of a breeze."
Leading scores on Thursday in the first round of the US PGA Shriners for Children Open in Las Vegas, Nevada (round halted by darkness to resume Friday. USA unless noted, par- 71):
63 - Peter Uihlein
64 - Seth Reeves
65 - Harold Varner, Robert Streb
66 - Jordan Spieth, Bryson DeChambeau, Kim Si-woo (KOR), Kim Whee (KOR), Sebastin Munoz (COL), Sam Ryder
67 - Lucas Glover, Martin Laird (SCO), Kevin Tway, J.J. Spaun, Jos de Jess Rodrguez (MEX), Scott Stallings