Ireland head coach Andy Farrell says his side are ready to be tested emotionally in Saturday's crunch World Cup Pool B encounter against holders South Africa in Paris.

It is the first time the Irish and the Springboks have met at the World Cup.

"That's what top teams do, they can compartmentalise what's going on to the reality of the big show," said Farrell.

"It's something that we've gotten better at certainly over the last couple of years and it's for occasions like this.

"We will be tested, our emotions will be tested but how we make sure we play the game that's in front of our face is pretty important."

Ireland, who have been top of the world rankings for 14 months, have won their last 15 Tests, a sequence that has included a series-clinching triumph over the All Blacks, an autumn internationals sweep against Fiji, Australia and Saturday's opponents, and this year's Grand Slam campaign.

But Saturday's meeting with the three-time world champions has been widely touted as the greatest challenge Ireland have faced under Farrell.

"They'll be relishing this game as much as we will be," Farrell said after announcing his team for the game.

"Two good teams going at it in form. It will be [about] who handles the pressure on the day the best."

When asked if he has prepared any big team talks before the game, Farrell added: "No, it's like every week. You prepare nice and early, review and learn the lessons and prepare for the next opposition.

"At the same time, you get a sense of when the players start to own the plan and it tends to be a little bit quicker in weeks like this and that's the case this week."

Sexton keen to improve despite superb start

Farrell was joined by captain Johnny Sexton for media duties on Thursday at the Ireland team's hotel in Paris.

Sexton has enjoyed a superb start to the World Cup after returning from a six-month absence, scoring three tries in the opening two games and surpassing Ronan O'Gara's Irish Test points record.

While the 38-year-old has thrilled the travelling Irish fans already, he insists there are still "plenty of work-ons" he has focused on before he attempts to unlock a mean South African defence on Saturday.

"[There were] some good lessons last week," said the fly-half.

"The best teams and best players learn in victory as well as defeat so it's important we learn some lessons last week, individually and collectively, and I think we've done that."

He added: "There's been no chat about emotions. We'll talk closer to the game about the different scenarios that might come up or the atmosphere and the occasion.

"But at the moment it's all down to what we need to do on the pitch."