Burmester hit six birdies and cruised through his round for a 262-shot total to overturn a three-shot deficit and claim his third win on the DP World Tour, which began its new season at the weekend.
The South African finished ahead of second placed compatriot Darren Fichardt, whose final round 64 included an eagle for a total of 265.
Defending champion Dan Bradbury from England also blitzed the course on the last day with his 64 taking him into third place on 267.
The top three finishers all qualified for The Open at Royal Troon in July.
Lawrence started the day three shots clear but was in trouble from the second hole, where he doubled bogeyed, and quickly saw his lead slip. He hit three more sixes for a final round 75 and a share of seventh place on 270.
“I tried to stay patient throughout the round,” said Burmester. “Thriston is a tough competitor so I knew I had to do something special and I was fortunate to do so.”
