Australia's Marc Leishman ended a trying 2015 on a high after cruising to victory in the Nedbank Golf Challenge to claim his first European Tour title and complete an Australian double.
However, Shane Lowry endured a frustrating final day as he finished 21 shots behind the winner.
It was a disappointing end to the year for Lowry, who hit his best round of the weekend, a two-under-par 70 that left him in outright 23rd place, on Saturday and looked poised to haul himself back up the leaderboard on the final day.
However the Offaly man bogeyed two of his first three holes to hinder any hopes of gaining early momentum, and double-bogeyed the eighth and ninth as he went round in 75 to finish in a tie for 26th.
Following compatriot Nathan Holman's win in the Australian PGA Championship earlier in the day, Leishman carded a closing 67 at Sun City to finish 19 under par, six shots clear of Henrik Stenson.
England's Chris Wood was a distant third on nine under with defending champion Danny Willett, Victor Dubuisson, Robert Streb and Branden Grace joint fourth on eight under.
Leishman pulled out of the Masters in April after his wife Audrey fell seriously ill with toxic shock syndrome, a rare but life-threatening bacterial infection during which she was put into an induced coma. She is now recovering but Leishman feared the worst and was prepared to give up golf to care for their two young children.
"I'm pretty happy to have this year over, to be honest," the 32-year-old said. "Audrey got very sick and I lost an uncle who I was very close to. This tops off what was otherwise not a great year. Three weeks ago we moved into a new house, so this will help pay for that."
Leishman began the day with a one-shot lead and found himself three ahead when he birdied the seventh and playing partner Stenson bogeyed the same hole after failing to get up and down from a greenside bunker.
Stenson bounced back with a birdie from 15 feet on the eighth and both players birdied the ninth and 10th before Leishman, who lost a play-off for the Open at St Andrews in July, extended his lead thanks to a superb approach to the 13th which span back to within inches of the hole.
Leishman, who defeated world number one Jordan Spieth in the singles in the Presidents Cup in October, also birdied the 15th and 16th and although Stenson chipped in on the next, the result - and destination of the first prize of £825,000 - was never in doubt.
"It's amazing. I'm so happy," added Leishman, who could reach a career-best 26th in the world.
"It's not very often you can walk up 18 with a good cushion and enjoy it."