Andy Farrell said his players' "resilience" stood out for him in Ireland's hugely impressive 13-8 win over defending champions South Africa in Saturday's no-holds-barred Rugby World Cup Pool B match.

The Irish were on the back foot for much of the second half but a mix of poor kicking at goal by Manie Libbok and sterling Irish defence saw the world ranked number one team secure a win that puts them on the brink of the last eight.

Neither head coach Farrell nor captain Johnny Sexton saw the victory as a statement win as the Irish seek to finally move beyond the quarter-finals in a World Cup, and even win it.

Farrell preferred to focus on his team's mental strength they showed as they extend their record Test winning run to 16.

"Our resilience which has been really good of late stood out most for me," said Farrell.

"Anyway, as you can imagine, it was a proper game with ebbs and flows and ups and downs.

"What also impressed me was how we stayed on point mentally."

Farrell, who has put the sceptics in their place from the early days of his reign after taking over following the 2019 World Cup, said the players had kept their cool as the pressure was piled on.

"It was a fantastic game and it was never going to be perfect," he said.

"The first half we got the rub of the green for position but we did not capitalise on that.

"The second half it was the reverse but we kept our heads and getting a couple of penalties at the end is a real plus of our performance."

Farrell said he was delighted that his players did not over-react and stayed in the zone when decisions went against them.

"I think as the competition goes on we need to be better, there were a few bits of inaccuracies," he said.

"But we were again able to find a way out of the trouble... We have got very good at not being too emotional and staying on task.

"Playing like that in the pool stage serves us well."

- 'Array of tricks' -

One area that went awry for the Irish in the first half were their line-outs, with hooker Ronan Kelleher's throws being picked off by Springbok jumpers.

However Sexton said it never worried him too much.

"I did not do anything. I let the guys look after themselves," the captain said.

"The Springboks have an outstanding defensive line but we will get it right next time.

"It had nothing to do with Ronan, it was a couple of bad calls."

Both Farrell and Sexton -- who exited to thunderous roars with around 10 minutes remaining -- said the last thing on their minds was a quarter-final.

Sexton said it had been that sort of thinking that had done them no favours in past World Cups.

"This honestly does not have any bearing on the title or the quarter-finals," said the 38-year-old.

"It was just another game, we are trying to make sure we get out of the pool.

"We cannot look beyond the next game, that is the biggest lesson we can take from past World Cups." 

Sexton had consoling words for Libbok, who has been under immense pressure due to his inconsistent place kicking.

"He did some outstanding things - he is a handful with the ball and has an array of tricks," said Sexton.

"Every kicker goes through a period of his career like that, I had one in 2011 World Cup.

"You get stronger off the back of it and become a better kicker for it.

"I don't think there is a kicker in the world who has not been through it. He is a fantastic player."

pi/gj