In 2011, Ireland kicked off their World Cup campaign in New Plymouth with a stuttering 22-10 win over the USA.

It was a scrappy win that offered little by way of optimism to an Irish team who had been expected to blow their opponents away.

Among the concerns were a young half-back duo who failed to find any sort of a rhythm as handling errors saturated proceedings.

It was a tough first international start for Conor Murray, who was playing alongside Johnny Sexton for the first time.

Sexton, the heir apparent to Ronan O'Gara's number 10 jersey, endured a torrid evening landing just one of his five kicks.

As Ireland searched for something positive to take out of an infinitely forgettable game, few would have pointed to signs of a promising half-back partnership developing.

Eight years on, it is a partnership that has delivered more than promise. Three Six Nations, two Lions tours, a Grand Slam and 164 international caps between them, to be precise.

Assuming they are picked to face New Zealand on Saturday, Murray and Sexton will make their 56th international start together, overtaking O'Gara and Peter Stringer as the most capped Irish half-back duo.

Is that a shock to Sexton?

"It is if you saw us play together at the start," he says.

"I didn't think we'd last much further after three or four caps to be honest."

A first for Sexton

Under Joe Schmidt, Sexton and Murray have been the most vital cogs in the Irish wheel, with the correlation between their individual performances and Ireland's fortunes glaringly obvious.

Saturday, by Sexton's own admission, marks their biggest challenge to date.

The reigning world champions stand between Ireland and a first ever World Cup semi-final.

For all he has achieved in the his career, Saturday's meeting in Tokyo will also mark Sexton's first start in a World Cup knock-out match.

He came off the bench in the 2011 defeat by Wales, and missed the loss to Argentina four years later through injury.

At 34 his importance within the team is, if anything, increasing.

"I love playing beside him," said Murray.

"He is such a leader, he understands what we are trying to do really well and gets it across to everyone."

Ireland's struggles in 2019 have been symptomatic of the issue that Murray and Sexton have faced throughout the year.

Returning from a long injury lay-off, Murray did not make his usual impression as Ireland's Six Nations defence fell flat on its face.

Sexton, too, has found injuries difficult to shake off and his absence was only too notable as Ireland fell to defeat by Japan in Shizuoka.

Against Samoa in Fukuoka last Saturday the pair returned to something close to their vintage form.

Directing the traffic, as Ireland sought to nullify their numerical disadvantage following the dismissal of Bundee Aki, Murray and Sexton led Ireland's charge to the knock-out stages with a bonus-point win that arrived with minimal fuss.

However against the All Blacks, a side undefeated in their past 17 World Cup games, Murray and Sexton will have to hit new heights in their 56th outing together.

"It's a little bit special to start that many Tests with the same guy," said Sexton.

"We've got a really good relationship now and hopefully it'll be as good as it ever has been on Saturday."