Canadian Nick Taylor hit a bogey-free 63 to claim a one-shot lead after the opening round of the Shriners Hospitals for Children Open.
Taylor, whose only win on the PGA Tour came in 2014, strung together an eagle and four birdies on the back nine to card an eight-under round in Las Vegas.
American Brian Harman is a shot further back, while five are tied for third including five-time major winner Phil Mickelson.
World number one Brooks Koepka is playing in his first tournament of the 2019/2020 PGA Tour, having recovered following stem cell treatment in his left knee as well as a wrist problem.
But his round of 70 was only good enough for a share of 85th place as he carded four bogeys across his round.
England's Ben Taylor shot 67 for a share of 20th, while Scotland's Russell Knox carded 68 to tie for 43rd.
The flagstick is your friend. 😃#MustSeeMoments pic.twitter.com/wLJQDXPZfB
— PGA TOUR (@PGATOUR) October 4, 2019
