Finau leads Charles Schwab Challenge after opening-round 64

Tony Finau sits atop the leaderboard at the Charles Schwab Challenge after shooting a 6-under 64 in Round 1 on Thursday.

Finau, whose best finish in Fort Worth was a T-19 in 2015, posted his seven-birdie performance at Colonial Country Club in the morning before strong winds drastically changed scoring conditions. Colonial played 1.65 strokes more difficult in the afternoon, according to the PGA Tour's Rob Bolton.

Jordan Spieth and Canada's Roger Sloan sit a shot back after Round 1. Spieth turned in a career-best day on the greens, gaining nearly 5.5 strokes with his putter.

Nine players are tied for fourth at 3-under, including past PGA Championship winners Jason Dufner and Jimmy Walker.

Notables Justin Rose (4-over), Jon Rahm (5-over), and Xander Schauffele (6-over) struggled in the afternoon wave. They carded five birdies between the three of them.

Round 2 begins Friday at 8:00 a.m. ET.