Els had a 1-over 73 after his triple bogey on the par-5 18th. Bickerton shot a 68 to finish at 13-under 275.
On his second shot, Els went for the green but the ball splashed into the water surrounding the green. The South African took a drop, but then went over the island green at the Leopard Creek Country Club.
He sent his next drop within six feet of the pin but missed the putt for a double bogey that would have forced a playoff.
'I'm shocked. I don't know what to say,' Bickerton said. 'I had no idea what was going on. I was busy signing a ball for a young boy when all of a sudden I got told I might be in a playoff, and then a few minutes later everybody's saying congratulations. I couldn't believe it.
'I went and shook Ernie's hand, but what can you say to the guy. He was gutted. But Ernie's won many times before and will win many more tournaments. That's golf.'
Els led by two strokes going into the final round. He started with three birdies on the first eight holes, but then bogeys on Nos. 9 and 11 set him back. Playing partner Lee Slattery had a 71 to tie for second.
Els then birdied the 14th and 15th holes, but bogeyed the 16th.
Even so, Bickerton wasn't thinking about winning.
'I thought I had a chance at the beginning of the round and when I made eagle three on the second. But when Ernie went three ahead I just started thinking about playing for second place,' the Englishman said.
Bickerton, however, stayed near the top of the leaderboard with a 20-foot putt for birdie on the 17th.
'That was crucial,' he said. 'I didn't look at the scoreboard, but it was a crucial putt.'