Max Homa made the dream start to his Nedbank Golf Challenge title defence by grabbing a one-shot lead after the opening round in South Africa.
The American, who claimed a four-shot win in last year's contest, mixed eight birdies with two bogeys on his way to a six-under 66 at Gary Player Country Club.
Homa birdied each of his opening three holes and followed another at the par-four sixth by taking advantage of the par-five ninth, seeing him reach the turn in 31, before holing from eight feet at the 11th to move to six under.
Dropped shots at the 13th and 15th briefly saw Homa lose his lead, but the world No 35 produced a birdie-birdie finish to move top of the leaderboard ahead of South Africa's Ockie Strydom.
"I thought I played really well," Homa said. "It was really tricky with the wind - it did a complete flip and it threw us for a bit of a loop, but I felt like I did a really good job of adjusting to it."
English pair Andy Sullivan and Matthew Jordan are three strokes back in tied-third alongside Pablo Larrazabal and Thorbjorn Olesen, while Christiaan Bezuidenhout is in the group a further shot back.
Thriston Lawrence - who challenged Rory McIlroy for Race to Dubai victory last season - opened with a one-under 70, while Abu Dhabi HSBC Championship winner Paul Waring started with a level-par 71.
Hatton jumps into contention at Saudi International
England's Tyrrell Hatton fired a bogey-free 63 to jump within a shot of the halfway lead at the Asian Tour's PIF Saudi International.
Hatton - who has top-six finishes in his last three worldwide starts - fired eight birdies, including five in a six-hole stretch from the second, during his second round at Riyadh Golf Club to move to 10 under.
The world No 16 is tied-fifth and one of eight players separated by a single stroke, as former Open champion Cameron Smith shares top spot with Joaquin Niemann, Logan McAllister and Peter Uihlein.
Smith posted a blemish-free 64 and Niemann carded a five-under 66, while McAllister matched Hatton's 63 and Uihlein - last week's winner at the International Series Qatar - signed for a six-under 65 despite bogeying two of the three par fives.
Steve Lewton, Jason Kokrak and Travis Smyth are alongside Hatton on 10 under, with former major winner Louis Oosthuizen two back and former Ryder Cup player Thomas Pieters within three of the halfway lead.
Graeme McDowell bounced back from an opening-round 74 to post a six-under 65 and make the cut on the number, while Dustin Johnson and Sergio Garcia were among the players to make an early exit.
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