The 21-year-old’s win was the second straight for a South African on home soil following Brandon Stone’s victory in the SA Open last week.
It also makes it three South African wins out of five this season after Charl Schwartzel’s victory at the Alfred Dunhill Championship.
Porteous finished two shots clear of countryman Zander Lombard as both men earned themselves a place at the British Open at Royal Troon.
England’s Anthony Wall, who led going into the final day, finished in a share of third alongside Swede Björn Åkesson, American Daniel Im and South African Justin Walters.
Congratulations @HaydnPorteous – 2016 Joburg Open champion. What a fortnight for South African golf. https://t.co/X3rkI04MqB
— The European Tour (@EuropeanTour) January 17, 2016Porteous’ victory comes in just his 22nd European Tour event and makes him the second youngest South African winner in European Tour history after Schwartzel at the 2005 Alfred Dunhill Championship.
He had missed both his cuts this season so far but has now earned a European Tour exemption until the end of the 2017 season and will move inside the top 250 in the Official World Golf Rankings.
The tour next moves on to the Gulf with three straight tournaments in Abu Dhabi, where Jordan Spieth and Rory McIlroy will start their seasons, Qatar and Dubai.
