The 23-year-old, who won by three shots at the Volvo China Open in Tianjin, admitted he was struggling to make a living when he was playing on the lower-grade Challenge Tour last year.
But Grace has now become just the second Q-school graduate to win three times on the European Tour, following Sweden's Johan Edfors, and the third youngest triple winner after Seve Ballesteros and Sandy Lyle.
The Pretorian, whose game had been singled out for praise by Gary Player, is also only the third South African to win three times in the same European Tour season, after major champions Ernie Els and Retief Goosen.
"I don’t know what is going through my brain at this time. It’s just amazing, awesome and just shows you the standard of golf that I am playing right now," he told media in Tianjin, according to an official transcript.
"To have three wins on the European Tour at this stage of my career is awesome."
In January, Grace won the Joburg Open, and then made it back-to-back victories a week later at the Volvo Golf Champions, also in South Africa.
On Sunday, he shot a 69 to close out the biggest win of his career at the $3 million China Open, ahead of defending champion Nicolas Colsaerts of Belgium. Grace is now fourth on the European money list, the Race to Dubai.
"If I think back now to last year and playing on the Challenge Tour and just trying to get back to the main Tour, and really just trying to make a living, it was tough at points. So to be here with three wins is amazing," he said.
"Everything is going great. It is nice to know that I don’t have to worry about a lot of stuff and I will just be able to play the game with a smile on my face and try to push on from here.
"I want to get better, I want to win more titles and I want to play the Majors and make a name for myself around the world."
After Louis Oosthuizen's win at last week's Malaysian Open, South African players have now won consecutive European Tour events in Asia with the Ballantine's Championship in South Korea due to start on Thursday.