The 26-year-old began the day with just a one-stroke lead over Lucas Bjerregaard but the Dane’s bogey at the first immediately eased the pressure and when Grace birdied the next he had a three-shot cushion.
As Bjerregaard imploded after a triple-bogey six at the short seventh, covering the back nine in 50, former Open winner Louis Oosthuizen, last week’s Nedbank champion, Danny Willett from Sheffield and Andrew Johnston all made a bid to challenge but all slipped up when they looked like getting close.
Oosthuizen finished second after a 69 at Leopard Creek Country Club in Malelane but Grace was well clear on 20 under after a four-under round of 68.
Johnston was third on 11 under, with Willett and Trevor Fisher jnr tied for fourth, 10 shots behind the winner.
“It’s been a phenomenal week,” said Grace, who becomes the first player to win the Alfred Dunhill Championship and the Alfred Dunhill Links Championship,
“It’s been a long year, a hard, year but now it’s a fairytale ending just before Christmas.”
Willett shot a 67 on Saturday to move to within two shots of the lead and at one stage yesterday, was second on his own as he chased a second successive victory. But he faded over the back nine and could only post a 76 to claim a cheque for 67,800 euros (£53,780).
He will learn on the updating of the world rankings if he has climbed into the top 50 and secured a place at next April’s Masters by virtue of his end-of-year finish. He is currently 56th.
English teenager Charley Hull has become the youngest winner of the Ladies European Tour Order of Merit – just 12 months after being named Rookie of the Year.
The 18-year-old from Kettering sealed the award after finishing joint fifth at the Dubai Ladies Masters. That took Hull’s season’s earnings to 263,096.69 euros (£208,500) and left her 29,808 euros (£23,633) clear of second-placed Frenchwoman Gwladys Nocera, who was tied for 11th in Dubai. Hull, who won her first professional title at the Lalla Meryem Cup in March and recorded nine top-10 finishes in 2014, said: “It’s good to win.”