American Johannes Veerman fired a final-round 69 for an "indescribable" one-shot victory in a European Tour event at sweltering South African resort Sun City on Sunday.
South African Aldrich Potgieter needed a final-hole par to force a play-off in a tense finish at the Gary Player Country Club 170 kilometres northwest of Johannesburg.
But the 20-year-old, who took a three-shot lead into the final round, needed three shots to reach the green, then two-putted for a bogey five.
Playing ahead of Potgieter, Veerman finished on five-under 283, one stroke head of Potgieter (75), Matthew Jordan (72) of England and Romain Langasque (71) from France.
Veerman, who was at the practice ground preparing for a possible play-off, battled to hold back tears when informed he was the champion, succeeding fellow American Max Homa.
"This win is indescribable. I have struggled for two seasons despite making huge sacrifices and now this happens," he told reporters.
"Although trailing Aldrich by several shots entering the final round, I believed I had a chance. But that is what I have often felt in recent seasons only to finish well down the field."
Ranked 209 in the world, Veerman believed his birdie four at 14 in 36 Celsius heat was a key factor in his success.
"I did great to get up and down in two after my drive and approach shots," added the 32-year-old native of Orange County in California.
It was the second European Tour triumph for Veerman after the 2021 Czech Masters by two strokes.