In an event that marks the start of the new European Tour campaign along with the Australian PGA Championship, which is running concurrently on the Gold Coast in Queensland, Jamieson carded a five-under-par 67 at Leopard Creek.
It left him sitting joint-third, one shot behind Schwartzel, a four-time winner, and Irishman Paul Dunne, who had a double-bogey 6 on his card but made eight birdies either side of that blip at the ninth.
Jamieson, who is determined to avoid taking it right to the wire again in terms of securing his card after finishing 106th and 107th in the Race to Dubai the past two seasons, came flying out off the blocks with a birdie-eagle-birdie start.
He made only two pars on the front nine, which he covered in 31, before mixing three birdies with two bogeys coming in to maintain the sub-70 scoring average from his final 10 events last season.
David Drysdale, who has become something of a South African specialist over the years, started his 13th consecutive European Tour campaign with a two-under-par 70 that contained five birdies, including three in his first seven holes after starting at the 10th.
Scott Henry, the third Scot in the field, was on the leaderboard after getting to four-under - the Qualifying School graduate started birdie-birdie before picking up other shots at the sixth and 11th - before undoing his good work over the last eight holes. The damage included a double-bogey at the 16th as well as a 6 at the final hole.
After bagging six birdies in a flawless effort, Schwartzel is now 128-under-par for his career in the event. That’s 83 shots better than anyone else and the former Masters champion is already the man to beat, even though Dunne, who had six top-20 finishes in his rookie season.