Branden Grace and Charl Schwartzel got an early start to putting a tough 2020 season behind them on Thursday as they carded opening four-under-par 68s in the Safeway Open in Napa, California.

It was the first event of the new PGA Tour season, and Scotland’s Russell Knox made seven birdies and an eagle on his way to a nine-under-par 63 and a one-stroke edge over three players on 64.

Grace started slowly with three pars and a bogey in his first four holes, but he ignited things with an eagle on the fifth. He followed that with three consecutive birdies ahead of the turn, but his homeward nine was quieter with two birdies being matched by two bogeys.

Schwartzel, who spent much of the last PGA Tour season inching his way back to the kind of form which made him a major winner in 2011, had matching nines of three birdies and a bogey.

Erik van Rooyen, who has garnered media attention as much for his trousers and his guitar-playing as for his golf, started the new season with a two-under 70.

Round two gets underway on Friday, and will be shown live on DSTV channel 213 from 10pm.