The native South African won the European Tour tournament after a near four-hour rain delay. Kingston's 72-hole total was 4-under 284.
Following a poor start (bogeys at one, six and nine), Wilson, the overnight leader, moved within one shot of Kingston's lead at the 10th, but Kingston steadied himself long enough to capture his first victory on the European Tour.
"That was the toughest day I have ever had," Kingston said. "I have had chances before and not made the most of them, but today, for once, I clinched it."
Wilson (73) finished 3-under 285.