Forward battle looms between Boks, Wales

London - South Africa and Wales are preparing for a struggle up front in what each believes will be a forward-dominated battle in their Rugby World Cup quarter-final at Twickenham on Saturday.

The Springboks have conceded just a single try in their last three matches while Wales allowed only two against them in their entire pool campaign.

South Africa coach Heyneke Meyer believes the game will be won or lost in the final 20 minutes and that in the end it will come down to who forces the most penalty mistakes out of the opposition.

"We are expecting an arm-wrestle right until the end," Meyer told reporters. "We're playing against a well-balanced side that always likes to mix things up when it comes to physicality.

"They have a good set piece and some strong ball carriers up front and in the back."

Meyer has made just a single change to his starting XV from the side that routed the USA 64-0 in their final Pool B match last week, with in-form wing JP Pietersen returning from injury to replace Lwazi Mvovo.

His bench is packed with experience as well, primed to come on in the closing stages and bring calm heads to what is expected to be a frenzied finish.

Wales have made three changes to their team with centre Tyler Morgan, prop Gethin Jenkins and flank Dan Lydiate all returning to the side.

"The physicality and intensity of the matches so far will stand us in good stead for what is going to be a huge battle against the Springboks," Wales coach Warren Gatland said on Thursday.

"They have grown game on game in this tournament and we know the challenge that faces us from a talented South African side."

The Boks have a dominant 27-2 win record against Wales, with one game drawn, but the second of those victories for the European side came at the end of last year when they triumphed 12-6 in Cardiff.

The South African side were depleted on that occasion as the fixture fell outside of the World Rugby match window, leaving them without their overseas-based players.

But it should still be a source of confidence for Wales that in a tight tussle against a physical South African team, it was they who won the day.

The winner will take on either New Zealand or France in the semi-finals.