Ireland relied on Sam Prendergast's boot and supersubs Bundee Aki and James Ryan to scrape past Wales 27-18 on Saturday to claim the Triple Crown and keep their Six Nations title defence on track.
Coach Simon Easterby, at the helm in the absence of Andy Farrell who has been seconded to take the reins of the British and Irish Lions tour of Australia, had gambled on seven personnel changes for the match at Cardiff's Principality Stadium in the name of squad rotation.
After opening victories over England and Scotland, Ireland were given a scare, before condemning Wales to a 15th straight test defeat by pulling away in the final quarter of an enthralling match.
"It was as tough as we expected, to be honest," said Easterby, the former Ireland flanker who spent the bulk of his career in Wales with Llanelli and the Scarlets.
"Going into the game there was lots of media speculation about how Wales are, the state of the game here, but we know the strength of Wales and the passion. We knew they'd be tough opposition."
Jack Conan and Jamie Osborne scored tries for the Irish either side of halftime, matched by Tommy Reffell and Tom Rogers for Wales.
Prendergast made the difference with four second-half penalties as part of a personal tally of 17 points from the kicking tee.
"We knew that Wales would come back into it if we gave them an opportunity and they did that," Easterby said.
"They had the ability to play well and play ball in hand. They made us work really hard for it."
Ireland lost Garry Ringrose for a dangerous tackle on Ben Thomas, but Aki came on after the 20-minute red card window, in the 51st minute, to shore up the Irish midfield. His dominant cameo performance featured some monster tackles, invaluable turnovers and devastating drives.
"Having someone like Bundee on the bench brings you physicality, it brings you a lot of energy to the group... good leadership," said Easterby, adding that the coaching staff would examine why the vaunted Irish scrum was regularly penalised.
Ireland captain Dan Sheehan said the team relied "heavily on our bench".
"They came on and made a massive impact, James Ryan and Bundee both made a huge impact to lift the boys with fresh energy. That was the making of the game there, relying on our bench to bring that energy."
NOT BOGGED DOWN BY PAST
Interim Wales coach Matt Sherratt, who had just a handful of sessions with the players after taking over when Warren Gatland left his role, said there were positives to take, from yet another defeat.
"My mindest on these three games is that I'm not getting bogged down by the past," said Sherratt, who will oversee Wales' trip to Scotland and the home match against England before returning to his job as Cardiff Rugby head coach.
"I'm not interested in what's happened in the past. I've just got to be authentic coach."
The match, he said, would "whet people's appetites in terms of, 'Can we build on this?'
"I've been coaching long enough (to know) there's always going to be a bounce like this. It's a fresh voice, a different attack. The challenge is trying to build on that bounce over the next couple of games."
Sherratt was keen to praise the players, saying: "We've had, really, three days' training so to replicate what we did Tuesday and Thursday as many times as we did, I was pretty pleased.
"We asked for two things before the game: show the crowd some emotion and some ambition within a structure, and we did that."
Wales skipper Jac Morgan said there was a feeling of pride regained after the confidence shone through in the Welsh performance – with the home side leading the world's second-ranked country 13-10 at halftime.
"Credit to Ireland, they're one of the best teams in the world, but we were in the game for most of it. I thought we were amazing today and the boys were great," he said.