JOHANNESBURG, Feb 10, 2013 (AFP) - Sterne, runner-up behind Stephen Gallacher of Scotland in the Dubai Desert Classic last weekend, fired an eight-under final-round 64 for a total of 260 in overcast conditions at Royal Johannesburg and Kensington Golf Club.
Pre-tournament favourite Schwartzel, who won the Joburg Open in 2010 and 2011 before relinquishing the title to Branden Grace last year, finished with a 66 for a 267 total over the 6942-metre course.
Chilean Felipe Aguilar (67), South African George Coetzee (67) and Portuguese Ricardo Santos (64) shared third place on 268 in the 1.3 million euro ($1,758 million) event co-sanctioned by the European Tour and Sunshine Tour.
South Africans Thomas Aiken (66), joint overnight leader Trevor Fisher junior (73) and Keith Horne (65) were a shot further back and Italian Lorenzo Gagli (67) and South African Garth Mulroy (67) ended with 270 totals.
The final round at a course in an upscale north-eastern Johannesburg suburb was disappointing with the expected showdown between overnight leaders Sterne and Fisher failing to materialise.
Fisher fell away badly after an eagle on the opening hole and a bogey-free eight-under round brought a sixth European Tour title to Sterne, who has been hampered by back problems.
"I played really good golf today and throughout the tournament -- that was probably the best final round of my career," said Sterne, 31, who missed much of the 2010 and 2011 seasons due to a form of arthritis.
"This is a big year for me. I have got off to such a nice start and hopefully I can keep it going. I desperately want to get back into all the Major championships.
"After so much time out with injury I did wonder whether I was ever going to win again. At one point the pain was so bad that I even wondered if I would ever play golf again."
Sterne laid his victory foundations on the front nine with five birdies -- including three in a row from the sixth -- while Fisher followed his eagle with three bogeys and a birdie by the turn.
A further three birdies on the inward half consolidated the advantage Sterne had created while a double bogey on 11 after a drive into trees and a second into a stream spelt the end for Fisher.
Leading scores after final round of Joburg Open over the par-72, 6942-metre east course at Royal Johannesburg and Kensington Golf Club Sunday (RSA unless noted):
260 - Richard Sterne 63-65-68-64
267 - Charl Schwartzel 68-65-68-66
268 - Felipe Aguilar (CHI) 67-66-68-67, George Coetzee 67-64-70-67, Ricardo Santos (POR) 70-65-69-64
269 - Thomas Aiken 67-70-66-66, Trevor Fisher jnr 66-62-68-73, Keith Horne 67-66-71-65
270 - Lorenzo Gagli (ITA) 67-68-68-67, Garth Mulroy 70-68-65-67
271 - David Drysdale (SCO) 68-67-68-68, Brandon Pieters 69-69-67-66, Jaco van Zyl 66-68-67-70
272 - Bryce Easton 65-70-70-67, Tommy Fleetwood (ENG) 68-66-69-69
273 - James Kingston 66-70-70-67, Justin Walters 71-67-67-68, Paul Waring (ENG) 71-67-67-68
274 - Tyrone Ferreira 66-70-71-67, Ricardo Gonzalez (ARG) 70-66-70-68, Hennie Otto 70-67-69-68, Lee Slattery (ENG) 67-72-67-68, Peter Uihlein (USA) 65-69-68-72, Danie van Tonder 68-70-67-69