The English Amateur championship semi-finalist shot a final round of 68 at Mossel Bay GC today, adding to previous scores of 70 68 70 for a 12-under-par aggregate.
He had trailed joint leaders Luke Jerling and Andre Nel, both South Africans, by one shot after shooting a two-under-par 70 on Saturday morning in the third round.
He dipped to 10 under with birdies at holes one and six before dropping a shot at the eighth.
A birdie at the 10th was followed by a bogey at 11, but he moved to 10 under again with a birdie at the 13th.
By that stage Jerling was one over for his final round and Nel four over, putting the Yorkshireman in the box seat as he looked to add this championship to the Gauteng North Open, which he won at Irene Golf Club three weeks ago.
And 24-year-old Bower cemented the victory by birdieing holes 16 and 17, another South African, Jovan Rebola, taking second place on nine under.
"I'm still fighting my swing a little, but I managed to get it in play and putted really well," he commented.
"I had no idea of the scores until I got in, but I had an idea I might be ahead as I knew I had a one-shot lead after nine this afternoon."
He had 20 birdies over the course of the four rounds, including four in succession from the 11th hole in round two.
Fourteen of his birdies came on the back nine, which he covered in 11 under over the four rounds as compared to one under on the front nine.
Bower is on a six-week trip as a member of England Golf's squad and will also compete in the Cape Province Open and the South African Amateur before returning home.
Following his success on week one he has placed third in the African Amateur Stroke Play Championship at Leopard Creek and tied 24th at Blue Valley Golf and Country Estate in the
South African Amateur Stroke Play championship in Gauteng, where he was under par in every round.
Nigel Edwards, England Golf's Performance Director, said: “Jamie’s success in South Africa is a result of the dedication, hard work and commitment to get better over the last number of years.
"I am delighted for Jamie as he has shown great attitude and determination to succeed and he is now reaping the rewards. I’m sure we will see Jamie continue to progress over the summer, he is a real role model for others to follow.”