Six Nations 2018: Ireland's new generation on the rise
Much of the build-up to Ireland's Six Nations win over Wales had focused on six players who had toured New Zealand with the British and Irish Lions.
Leigh Halfpenny, Dan Biggar and Liam Williams had recovered from injury to strengthen Warren Gatland's Welsh team.
In contrast, Joe Schmidt was suddenly without the services of Tadhg Furlong, Iain Henderson and Robbie Henshaw.
Schmidt had to turn to his reserves and ask them to step into the breach in the biggest game of their young careers.
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Tight-head prop Andrew Porter was tasked with anchoring the Irish scrum in his first Test start while James Ryan, who impressed in the opening round win over France, replaced Henderson in the second row and Chris Farrell was pressed into action in the centre.
"James Ryan and Andrew Porter - what a huge stage to come in to and you have to be hugely impressed," said Schmidt after the bonus-point win.
"Chris Farrell being man of the match is super. He was really well supported by Bundee Aki, who only has a handful of caps, and Jacob Stockdale has a nose for the try line."
From Under-20s in just 20 months
As they lined up side by side for the anthems in front of their family and friends and 51,000 complete strangers on Saturday, it would not have been lost on Ryan, Stockdale and Porter that it was 20 months since they had played together in the final of the World Rugby Under-20 championship.
Ireland lost to a Harry Mallinder-inspired England side in Manchester but the team had beaten Wales, Argentina and reigning champions New Zealand on their way to the final.
Ryan and Stockdale, both 21, and Porter, 22, are the first members of that generation to break into the senior team but already appear at home in the Test arena.
"It's not a bad start to an international career," grinned Stockdale after his two tries against Wales, which took his tally to eight tries in seven Tests and to the top of the Six Nations try scorers' table with four from the opening three rounds.
"My goal had been to play Six Nations by the time I was 23. That kind of got accelerated with Simon Zebo going to France and I'm pretty happy with the way I've taken my opportunities so far."
Already a fixture in the Ulster starting team, Stockdale's career path remains on an upward trajectory since making his international debut against the United States in June 2017.
His decision making in defence is an area that still needs improvement but he believes he has already learned a great deal since he was first called into the senior camp.
"I think it's just how to survive at the top level of rugby," added Stockdale.
"You learn a lot about yourself and how you train and how you work when you're not on the rugby pitch.
"I think that has probably been the biggest thing - there's a lot more behind the scenes work that I had to learn how to do, which I didn't do before and that's probably the biggest learning point for me."
Ryan was the captain and talisman for the Irish Under-20s in 2016 and the 6ft 8in second row went on to make his Test debut before he had even played for Leinster.
"He probably hasn't changed an awful lot," said Stockdale of his team-mate.
"I've played with James since Ireland Under-18s and he came in and was made captain straight away because the guys knew that he had a really good leadership quality and it was the same at Under-19s and Under-20s.
"It's just probably something that he has - if that makes sense. There are guys who are natural leaders, who kind of stand out, like Rory [Best], Pete [O'Mahony] or Johnny Sexton. Then in the younger realm, you have James Ryan."
Although he missed the eight-try defeat of Italy through injury, Ryan started the wins against France and Wales and is already being touted as the next Paul O'Connell.
"It's humbling to be compared to somebody like that but I think it's probably not really appropriate," said Ryan, who does not appear to be fazed by the comparisons.
"He's one of the greats of Irish rugby and for anybody to be compared to somebody like that is humbling but I don't think it's appropriate to be honest.
"I've spoken to him a couple of times. We've had a few joint sessions with the Under-20s this season and caught up briefly then. Hopefully down the line I can chat to him for a bit longer.
"He just has a wealth and knowledge and experience. Whatever he says, I try to soak it in. He's been there and he's done that."
Ryan made a team-high 12 tackles in the dramatic win over France in the opening round of the championship but he was asked to perform a very different role during the full 80 minutes against Wales - carrying 11 times for 21 metres but making just two tackles.
He was surprisingly honest about his own performance. "I don't think I'll ever feel at home," he said. "Some of the games are definitely a step up just in terms of the physicality.
"I think in the second half, we kind of got on top of them and we could have finished them off a couple of times.
"There was one incident where we were on their line and Dan Leavy made a carry and I'm braced over the ball and I kind of get dominated, pretty much.
"Well, I don't kind of get dominated, I do get dominated - and as a result, [Conor] Murray is under pressure and we end up spilling the ball and giving them an easy out.
"Moments like that we could have been better at and as a result we could have put them away earlier."
Such a self-critical approach, coupled with a relentless hunger to learn, shows why Ryan, Stockdale and Porter are so well-placed to have long and successful international careers.