The victory marked consecutive 40-point tallies on their UK tour after they beat Scotland 41-3 in Edinburgh last Friday. They will next face a tough clash against England in London on Friday before departing for the World Rugby U20 Championship in France.

"I am pleased with the performance and I thought our defence, lineouts and scrums went well," said Roux of the six tries to one result in Cardiff.

"It was a physical match and we stood our ground and dominated in the contact. I am especially pleased with our defence.

"It is a pity we conceded one try, but they were on our tryline at times and we had to defend several phases, so I thought that was excellent. It showed the players' commitment."

It was only in the second half that Roux's boys found their feet, having only gone into the changeover with a 10-0 lead.

"I think we still have some work to do on our attack. But that is why are playing these matches. We would like to learn from them."

Roux is well aware that they will have to be at their best on Friday when they meet England at the Sixways Stadium in Worcester. Apart from the fact that the English are second-favourites for the world title behind New Zealand, the Junior Springboks only have two full days to prepare for their final warm-up match.

"It is going to be tough with a two-and-a-half days to go before the match against England, but we are trying to make it as tough as possible for the players," said Roux.

"We are expecting a difficult match, as they are fresh and will be ready for us, but that is exactly what we wanted before going to the World Rugby U20 Championship."

Recap of Tuesday's match:

Wales 5 (0)

South Africa 41 (10)

Wales - Try: Corey Baldwin.

South Africa - Tries: Muller Uys, Wandisile Simelane, David Coetzer (2), Daniel Jooste, Tyrone Green. Conversions: Gianni Lombard (4). Penalty goal: Gianni Lombard.