Charley Hoffman leads Charles Schwab Challenge, Scottie Scheffler struggles

Scheffler was not alone as blustery conditions and firm, re-laid greens made scoring difficult, Hoffman bucking the trend as he missed only two fairways in a bogey-free 65.

"It's one of those golf courses you want to be aggressive on because you have some mid and low irons in, but you can't get too aggressive out here because the greens are small and it's hard to get up-and-down," Hoffman told pgatour.com.

"So I would say it was somewhat an easy 5-under, which are nice. They're not always that way, but it was low stress."

Scheffler was seven behind Hoffman after a two-over-par 72 at the restructured Colonial Club, Forth Worth — his first opening round over par of the season, which included his first triple bogey of the year.

The world number one had played 41 consecutive rounds no worse than par before the third round of last week's US PGA Championship, the day after he was arrested on his way to the course for not following police orders following a fatal collision.

Scotland's Martin Laird and Open champion Brian Harman were also bogey-free as they joined Tony Finau, Davis Riley and South Korea's SH Kim a shot off the lead.