In the context of an intensely demanding Pool B, this proved to be a near-perfect night for Ireland in Nantes. An attacking bonus point was secured by half-time, the game all but won. The inspirational and insatiable captain, Johnny Sexton, crossed for his third try of the tournament, overtaking Ronan O’Gara to become his country’s leading points scorer.

A try, four conversions and a penalty made it a 16-point return for Sexton, moving his total to 1,090. The Leinster fly-half downplayed the record afterwards, saying another fluent Irish victory was not about individual achievements, at the same time conceding it was a “lovely personal milestone”.

“He deserved to have it like that, didn’t he?” said the Ireland head coach, Andy Farrell, of Sexton’s record-breaking moment. “I think he would say that’s his job, to kick goals and score tries every now and again. But that doesn’t make him. What does make him is how he leads his men every single weekend.”

Ireland scored eight tries, making it 20 in two matches, but perhaps most importantly they were given a significant physical test by Tonga, who were as hungry and well-drilled as Farrell had predicted.

Boasting four former New Zealand internationals in their starting XV, Tonga hit hard and often. They competed fiercely at the breakdown in the first quarter, winning penalties and generating turnover ball.

It was clear Ireland would have their work cut out – the problem for Tonga was their own failure to build any kind of lasting continuity in attack for themselves. With a quarter of the match gone Ireland were being held at 3-3, the fly-half William Havili having cancelled out Sexton’s early penalty with a sweet strike of his own. But the second quarter was a different tale, and predictably it was the awareness of Sexton that first ripped open Tonga’s defence. The fly-half fizzed a perfect pass for the sprinting Caelan Doris, charging into the 22, who offloaded smartly for Tadhg Beirne to stretch for the tryline under the posts on 21 minutes.

It had been nip and tuck, but when Solomone Kata needlessly followed through on James Lowe, the result was a penalty kicked for the corner by Sexton. Doris barged over following another smooth set piece – significantly, after a few hiccups against Romania last week, Ireland won 21 of 23 lineouts.

Mack Hansen was soon cutting in from the right after more fluid passing. The wing collected a bouncing ball and danced past Salesi (formerly Charles) Piutau and beyond several more challenges to cross for Ireland’s third try.

Two minutes before half-time, another slick Irish passing move ended with Garry Ringrose offloading to Sexton. The irrepressible 38-year-old glided under the posts and scored, celebrating demonstratively with his teammates having surpassed O’Gara.

That four-try burst seemingly overwhelmed Tonga but to their credit, they promptly caused problems at the other end. The Ireland No 6, Peter O’Mahony, was shown a yellow card before Vaea Fifita’s sniping score gave the Pacific islanders some hope. The half-time scoreboard read 31-13, with Havili registering two neat penalties and a conversion.

After half-time, with Sexton withdrawn and Ireland’s front row freshened up, Havili kicked another penalty and narrowed the gap to 15, with Ireland’s replacement front-rower Rob Herring then denied a try for a double movement.

But the Tongan defence was visibly tiring, with Lowe and then Bundee Aki (twice) crossing to put the match beyond Toutai Kefu’s spirited players. Herring eventually got his try with the clock in the red.

“We’re delighted to get five points against a very good team,” Sexton told ITV. “That’s what tonight was about. We move on. We’re concentrating now on a massive game next week. Playing against the world champions – it’s going to be very special.”

All eyes on next Saturday in Paris, then. The Springboks will be a rather different proposition, but on this evidence, Ireland have nothing to fear.