Mthembu, who won the Comrades Marathon in 2014, was the strongest of the South African runners when he finished in a stellar second place overall behind Japan’s Hideaki Yamauchi, breaking the South African 100km record set by legend Bruce Fordyce in 1999 in the process.
Mthembu has been in good form throughout 2016, collecting a third place finish at the Comrades Marathon along the way.
The 33 year-old knew that 100km was going to be a completely different challenge though but was surprised by his performance.
“It was the first time I had ever ran that distance so I really didn’t know what to expect from the race,” Mthembu said on his return to South Africa.
“To be able to come second was incredible, but I think that the most important thing was that we were able to win the overall team title.
“We worked well together and although we had some problems, I knew that the team was going to be strong and it’s an amazing time for ultra-distance running.
“It just shows everyone that the new era in South African running is upon us.”