Improved putting enabled major victor Louis Oosthuizen to take a one-shot lead in the South African Open on Saturday after carding a seven-birdie 64 in the third round.
Grace's efforts at the Randpark Golf Club secured him a place at this summer's Open Championship at Royal St George's along with fellow qualifiers Armitage and Ahlers.
It was the 31-year-old Grace's ninth European Tour title and first victory at the South African Open.
It was Grace's first victory since she lifted the Nedbank Golf Challenge trophy in November 2017, and also her fourth victory in the European Circuit in her homeland, which should be enough to raise it back to the top 100 in the world rankings.
"I spent time on the putting green after the second round and it paid off", said Oosthuizen who is ranked 20th in the world. I can't remember the last time I played this well and was so in the zone - even from the first hole - I had a good look at birdie at the first.More news: Mitch McConnell welcomes end to Nancy Pelosi's 'one-woman blockade' on impeachment
"I dug a pretty little corner out of three and it started from there". This means so much to any South African, winning on home soil.
After holing the winning putt, Grace celebrated with his wife, Nieke, and walked off the green with their young son, Roger, in his arms. "It's a good birthday wish to my missus (Nieke) today".
South African Jaco Ahlers (68) is alone in third on 13 under-par, while a bunch of five players, including home favourite Brandon Grace (67) are a further shot back, but will feel in contention going into Sunday.
The 31-year-old is coming off a torrid 2019 which saw him slide as low as 129th in the world rankings, although he did show signs of the Branden Grace of old when he finished tied for third at the Alfred Dunhill Championship last month.
Oosthuizen seemed boring as he made his way home for a 68 that could have been several better shots if he had not put on such a cold putter, and he will be allowed to reflect on what he could have been despite firmly defending his title.More news: Auto industry cautious as China starts 2020 with 2% sales decline forecast
"It was just an incredible day and I'm glad I could finish it off". What an fantastic day it was.
"This is the one I wanted".
But while playing the ninth, he would have heard huge roars behind him when Oosthuizen's Iron Seven from the tee in the eighth par 211 yards had enough charge to clear the water and throw on the green before falling into the water. hole for an fantastic ace.
The 2010 Open champion had seven shots on goal to take advantage of a stroke over the Englishman Marcus Armitage, who ran across the peloton with a superb 62, bringing him to 14 sous.More news: Kylie Jenner's longtime assistant quit her job to become a full-time influencer