The third biggest winning margin in European Tour history was achieved at Leopard Creek a week after last year's US Masters champion won in Thailand by 11 shots.
Only Tiger Woods and Ernie Els, who won the 2000 US Open and 2005 Asian Open by 15 and 13 respectively, have left the best of the rest trailing so far behind in the circuit's 40-year history.
Schwartzel, 10 clear with a round to play, added a three-under-par 69 either side of a two-hour thunderstorm delay to take his eighth Tour title - five of them in South Africa - with a 24-under-par total.
In the Thailand Championship he was 25 under, and for the past five weeks - they started with finishes of fifth, third and second - he is a staggering 84-under.
France's Gregory Bourdy, his closest challenger for virtually the entire weekend, took a double-bogey seven on the final hole and that elevated Swede Kristoffer Broberg, four times a winner on the Challenge Tour last season, into second place.
Bourdy shared third with Scotland's Scott Jamieson, who last Sunday captured the Nelson Mandela Championship in Durban, defending champion Garth Mulroy and England's Andy Sullivan a month after he came through the Tour qualifying school.
Schwartzel also continued a remarkable record at the course on the border of the Kruger National Park. He won his first Tour title there in 2004 and has had four runner-up finishes.
"It's always been a special place for me," the 28-year-old said. "This is where I can almost say my career started and it's always stayed close to my heart. It's nice to have continued my form from last week. I was saying a month and a half ago it's been a pretty disappointing year.
"Slowly and surely I started to swing the club a lot better, back to how I did when I won The Masters, and I actually got excited to play again.
"It started at the SA Open and from there got better and better. It's been a pretty good year now!"
Schwartzel's lead was down to seven when he three-putted the eighth, but he spun his approach to three feet on the next and after the weather hold-up collected more birdies on the 12th, 13th and par-five last.
Fellow countryman George Coetzee's best-of-the-day 65 lifted him into joint 10th place and came after results elsewhere had guaranteed he stayed in the world's top 50 and earned himself a Masters debut next April.
Also qualifying by the same route for a first trip to Augusta are Welshman Jamie Donaldson, Belgian Ryder Cup star Nicolas Colsaerts, South African Branden Grace and Dane Thorbjorn Olesen. Geoff Ogilvy would have denied Olesen if he had had one less shot at the Australian PGA Championship, where he finished in a tie for fourth place.
Others to book their Masters places through the end-of-year top 50 are Scot Paul Lawrie, Italians Francesco Molinari and Matteo Manassero, Spaniard Gonzalo Fernandez-Castano, Denmark's Thomas Bjorn, American Bill Haas, Australian Jason Day and Japanese player Hiroyuki Fujita.
Coetzee said: "My dream has never been just to play in The Masters. That's not the job description - I want to play in those majors and I want to win all of them. After three days of scrapping around this week I got things together. It's Augusta - it's the one major with a limited field, it's the best.
Peter Lawrie was the only Irishman left in the field after the cut and he finished in a tie for 15th place following a closing 71.