Michael Hoey dropped five shots in the last five holes to card a four-over-par 74 in the final round of Nelson Mandela Championship in Durban.
The Belfast player finished two under for the tournament, which was reduced to three rounds because of rain delays.
Hoey, who also had rounds of 65 and 69, was well placed before double bogeys at 14 and 18 and a bogey at the 17th.
Ireland's David Higgins (70) ended eight under while Dawie van der Walt won by two shots on 15 under.
Damien McGrane joined Hoey on two under and in a tie for 50th following a 69.
Russian Open champion Hoey was sharing 11th place when play finished on Friday.
Hoey failed to make the cut at the recent South African Open, then withdrew from the Alfred Dunhill Championship but spoke of "hitting the ball better" after finishing in the top 10 at a tournament in Mauritius last week.
The first day was brought forward by a day to its Wednesday start to avoid a clash of its final round and Sunday's funeral of the former South African president.