Sterne had five birdies in his first eight holes Sunday and closed with back-to-back birdies in his 64 and a 72-hole total of-27-under 260. It was his second Joburg Open win but first European Tour title since December 2008. He's won six times overall.
Trevor Fisher Jr. and Sterne started the day tied and Fisher took the lead with an eagle at the first hole. But he staggered badly from there with three bogeys on the front nine and a double bogey and a bogey on the back for a 1-over 73 and tournament score of 18-under, which tied for sixth.
Charl Schwartzel shot 66 Sunday and finished second at 20-under with Ricardo Santos, after a final-round 64, ending up tied with Felipe Aguilar and George Coetzee, who both had final rounds of 67, for third.
Down a stroke after the first hole, Sterne tied Fisher with a birdie at the second and moved ahead when Fisher had a bogey at No. 3. He pulled well ahead with a string of birdies over Nos. 6-8 while Fisher had bogeys at 6 and 7.
Sterne cruised in the second nine with six pars and a birdie at 13 before his closing two birdies.