He needn't have worried.

Homa holed a 16-foot birdie putt on the last to complete a six-under 66 on Thursday and join Nicolai Hojgaard, Dan Bradbury and Vincent Norrman in a share of the first-round lead in Sun City in the penultimate event of the DP World Tour season.

The American was bogey-free around the Gary Player Golf and Country Club, which he barely knew after a shortened build-up that included a practice round on Tuesday being wiped out by rain.

The World No.8 Homa hasn't played since the Ryder Cup outside Rome where he collected three-and-a-half points as the highest scorer for the United States in their loss to the Europeans.

No wonder he said it was "mildly shocking" that he went so low.

"I learned I can be uncomfortable and play well, which is cool," said Homa, who went on what he described as a "life-changing" safari trip with Justin Thomas over the weekend to make the most of his time in Africa.

"Sometimes golfers, and myself in particular, try to feel as perfect as possible going into events and I felt far from that.

"I knew it wasn't going to be perfect so I think I had a nice game plan and tried to settle me into feeling a little bit off out there and almost dumb it down a little bit. That's what I learned."

"I learned I can be uncomfortable and play well, which is cool." – Max Homa.

Homa was happy to find the centre of the green and take his chances with some long putts in the early holes. He made two of them – including from 25 feet at the 6th – and also made birdie from 4 feet at the 8th, before picking up three more birdies in his last five holes.

Norrman – a Swede with two wins since July – also had a bogey-free round containing six birdies while Bradbury rolled in a 75-foot putt for eagle at his last hole – the 9th – to join the leaders.

Hojgaard, who played against Homa at the Ryder Cup, had eight birdies and was the first to set the 6-under target at an event some like to label "Africa's Major."

Adrian Meronk, Ryo Hisatsune and Julien Guerrier were tied for fifth, a shot off the lead, after 67s while Tommy Fleetwood – seeking a third straight win at the Nedbank – double bogeyed the last after hitting his approach into the water and shot 71.

Thomas, who like Homa received an invitation to play, shot 72, while Jason Scrivener, the one Australian in the field, was one-under after his 71.