The South African took a three-shot lead into the final round and never looked like losing despite dropping two shots in his first nine holes as he finished 15 under par.
Schwartzel finished four shots ahead of France's Gregory Bourdy in second and five clear of another Frenchman, third-placed Benjamin Hebert after a two-under-par fourth round.
Bourdy hit four consecutive birdies before a triple-bogey on the par-3 seventh hit his challenge.
He launched a mini-recovery late on when he claimed birdies on the 15th and 16th. Hebert dropped a shot on the 18th to hand Bourdy outright second.
Englishman Matt Ford finished tied for fifth after rising up four places thanks to a round of 70, which left him eight under par overall, while Eddie Pepperell was a shot back.
But Schwartzel eased to victory, mainly thanks to a 66 and 67 in his first two rounds. Bogeys at three and eight briefly stalled Schwartzel's charge, but birdies as 11, 13 and 14 ensured he maintained a comfortable lead.