South Africa lock Pieter-Steph du Toit has said that his overriding emotion after seeing his side progress to the semi-finals of the Rugby World Cup was one of relief.

The Springboks overcame Wales in an absorbing match at Twickenham that saw the lead change seven times before Fourie du Preez's late try proved to be the winning score.

Heyneke Meyer's side will now face New Zealand in the semi-finals next Saturday as they attempt to move one step closer to becoming the first ever three-time world champions.

After the victory, Du Toit, who was one of the changes Meyer's lauded as having a match-winning effect, spoke to Sports Mole about the victory.

Can you sum up your emotions after that game?

"I'm quite relieved. It was a very tough game, Wales played really good rugby. I think it was a very tough game for both teams. Their defence were amazing for the whole game. They rushed us and kept us behind the gain line, but the special skill set that each person brings to this team made Fourie score that try at the end."

How important is Du Preez to the team when he is in this sort of form?

"He's an amazing player and a great captain as well. He brings a lot of calmness to the team. We know what is expected of each other and someone like that in your team just shows you what they can bring."

You have been one of the strongest teams ever since that monumental shock against Japan in your opening game - do you think you needed a wake-up call like that?

"We'll always carry Japan with us throughout the World Cup as motivation. It's something we never want to feel again and we say it before each game - we don't want to feel that again. We've got to win each game."

It is the All Blacks in the last four and they looked highly impressive in their drubbing of France. Is that the semi you would have rather avoided?

"No, we don't really care. It doesn't matter which team you play, everyone in a semi-final is good enough to be there. I think it's going to be a cracker of a game as well."

How confident are you that you can beat New Zealand?

"We're really confident. If we don't believe, who else would believe? I think if our motivation and our mental strength is right then we have every chance to win."