Schwartzel started the final round with a pair of birdies and then when he birdied the par-four sixth hole, he had drawn level with Stone.
The Rustenburg-born golfer immediately birdied the sixth himself though, and added another birdie on the seventh.
Trying to keep a low ball-flight on the long par-four eighth, the second toughest hole on Sunday, Stone took a Driver off the deck, but put his ball in the rough, leading to a bogey.
“It’s my most fun shot, but I just hit it a bit heavy,” Stone explained afterwards.
So he went to the turn one-under-par and just one ahead of Schwartzel, but Stone produced a phenomenal change of gear on the back nine, rattling off pairs of birdies on 10 and 11 and 13 and 14. It was all part of the plan he said, showing his maturity.
“On the front nine I was tied for the lead at one stage and it was reminiscent of the SA Open. But I knew my game-plan was to be one or two under for the front nine and then try and score on the back nine, and I was able to get some momentum going,” Stone said.
By the time Stone bogeyed the par-four 17th, there was nobody anywhere near him.
There had been signs of fight from Schwartzel as he sank a 20-foot putt for birdie from the fringe on the par-four 11thhole, but there were inconsistencies in his game.
The rot began on the par-five 13th when, after a superb drive down the middle of the fairway, he put his approach shot into the greenside bunker.
He took two shots to get out of the sand, and another two putts to finish the hole, the bogey he made meaning he was five behind Stone when the youngster birdied the same hole a few minutes later.
There was no coming back for Schwartzel, in fact there was even more pain.
On the par-five 15th he twice hit into thick rough before finding the water, eventually signing for an eight, and then his tee-shot on the par-three 16th also went into the drink, leading to a double-bogey.
Even though Schwartzel birdied the last, he was left in a tie for fourth on 12-under-par with compatriot Thomas Aiken (69), Frenchman Benjamin Hebert (72), Scotland’s Scott Jamieson (69), Spaniard Carlos Pigem (69) and England’s Graeme Storm (68), after a 74.
It was not a good day either for the other two golfers who were tied for second overnight with Schwartzel.
South African Keith Horne was off to a terrible start with two bogeys and a double in his first four holes, and was left in a tie for 11th on 10-under-par after a 76, while Hanson was also blown off course early on with a seven on the par-five second hole, finishing with the same score as Horne.
Richard Sterne was the big beneficiary of all that carnage, shooting an impressive 67 to climb from seventh to second on 15-under-par overall.
Young Belgian Thomas Detry was also impressive in shooting a 68 that left him in third place on 13-under.
Although it seemed an almost effortless victory for Stone, he said he had to sweat both literally and figuratively in the 40 degree heat.
“It certainly wasn’t stress free and I was absolutely cooked at the end, I was the first guy into the shade whenever there was a break in play. But it’s probably the best I’ve played, my ball-striking was superb from the first hole to the last and there wasn’t a hole that I was really in trouble on all week. To shoot 22-under around here is not a simple task, it’s quite something,” an ecstatic Stone said.
It was an amazing display of golf and deserving of the cool R2.8 million winning cheque Stone received.