Homa started his round at the Gary Player Country Club in Sun City with three straight birdies on Thursday, and had two more on the front nine before dropping two shots with bogeys on the back nine. 

Strydom's opening round of 67 included four birdies, an eagle and a bogey. 

After missing out on qualifying for the Tour Championship in August, Homa had made just two tour-level starts. Last year, he became the fifth American to lift the trophy in South Africa.

The six-time PGA Tour winner is trying to become the eighth player to successfully defend his title at the tournament — and the first American to do it since Jim Furyk in 2006.

Elvis Smylie carded a one-under round in Sun City. PHOTO: Getty Images.

Homa is among three players in the field ranked in the top 50, along with Corey Conners — who opened with a 72 — and Thriston Lawrence, who shot a 71.

Australian Elvis Smylie, fresh from his triumph in the Australian PGA Championship,  had a decent start with a one-under 71 to lie in joint-12th place, five off the pace.