Goalkeeper Ronwen Williams has praised South Africa's resilient backline as they prepare to face Nigeria in Wednesday's TotalEnergies CAF Africa Cup of Nations semi-final.

Williams has been integral to Bafana Bafana's memorable run, keeping three clean sheets in five matches. 

But the SuperSport United stopper was keen to highlight the efforts of his defensive unit ahead of their toughest test yet.

"The attackers and midfielders have played well but the back four has been amazing throughout the tournament," Williams said.

"We know it will be a very tough game against Nigeria but we're looking forward to it."  

Williams also paid tribute to Nigeria keeper Stanley Nwabili, who has excelled at the other end.

"I'm so happy for him, it's amazing he said I'm an inspiration. Inspiring someone is a great feeling," remarked Williams.

The two men will share the Stade de la Paix pitch on Wednesday as both nations chase a place in the final.

"He's been unbelievable this tournament but hopefully he concedes and we reach the final," Williams added light-heartedly. 

South Africa have exceeded expectations under coach Hugo Broos and will need another huge effort against a talented Nigeria outfit.

But Williams clearly has great belief in his experienced back four to keep the Super Eagles at bay once again.

With a historic opportunity in sight, the Bafana Bafana keeper knows the foundations for success lie in their miserly defence.