Els shot a 4-under 68 in the final round and benefited from the shocking collapse of third-round leader Ulrich Van den Berg, who had three bogeys and two double-bogeys on Leopard Creek's back nine.
Last year's win was Els' third at the dunhill championship. Another victory this year would put him in exclusive company.
Excluding major championships and WGC tournaments, only three other players have won a single European Tour event four or more times: Bernhard Langer, Nick Faldo and Seve Ballesteros.
Els should feel comfortable over the next month or so as the European Tour plants itself in his native South Africa, where two more events (South African Airways Open; Joburg Open) are scheduled to take place before mid-January.
The Golf Channel will have coverage of all four rounds beginning at 9 a.m. (ET) each day. The South African Airways Open is next week.