Springbok captain Victor Matfield paid tribute to his side's staunch defence as the world champions withstood a late rally from Wales to win 25-29 at the Millennium Stadium.
The victory kept South Africa's hopes of a Grand Slam alive after they brushed aside Ireland last weekend.
South Africa were 17-9 behind at the break but scored 17 unanswered points in the space of seven minutes to grab the initiative from Wales.
Wales refused to cave in and mounted a fierce late rally but couldn't breach the green wall.
"I'm very proud of the boys, they showed great character," said Matfield. "Wales put us under pressure and it was a great game for the spectators to watch.
"Well done to Wales, they really came out and played well. "(Defending) is something we really worked hard on (in training) and it came through and we were happy with that," he added.
Referring to a possible Grand Slam, Matfield said: "I don't know. There's still a fair way to go. We're focusing on Scotland and that's going to be another huge game. We will enjoy tonight and then start fresh from zero on Monday again."
Dodgy tattoos, carthorses, Avatar and soft chins are revealed by Wales Sevens players Tom Williams and Sam Cross as they profile the Wales Sevens squad taking part in Hong Kong this weekend in the latest round of the HSBC Sevens World Series.
The youngest member of the Wales Women's squad, Keira Bevan, is hoping to repay the faith shown in her when she starts her first Six Nations game against Italy tomorrow evening in the final round of the championship.
Sevens head coach Gareth Williams is a happy man after drafting in full internationals Rhodri Williams and Adam Warren for the next two rounds of the world series in Hong Kong and Japan, as WRU TV's Graeme Gillespie discovers.
Gemma Rowland has had a 'whirlwind' start to her international career with Wales. Despite losing to France, she is confident Wales Women can bounce back and claim a rare Triple Crown against Ireland on Sunday, as WRU TV's Graeme Gillespie discovers.