Leinster may have been through a rebuilding phase this season but the way they defeated Wasps in the quarter-finals has given the Irish province confidence ahead of their European Champions Cup semi-final away to French giants Clermont on Sunday.
With Lions stars Jamie Heaslip and Rob Kearney both injured, and the English Premiership leaders coming to Dublin, Leinster's home city, with a glittering array of international stars, the last-eight clash against Wasps back on April 1 provided a perfect testing ground for their new-look team.
Having already redeemed their European reputation, with a return to the knockout stages after last season's hugely disappointing campaign that saw them lose their first four pool games in a row for the first time, coach Leo Cullen's new-look side were in no mood to settle for anything less than victory.
With just three of Leinster's starting XV in the quarter-final that kicked off in their 51-10 defeat by Wasps last year, they turned the English side over with ease, winning 32-17 to book their place in the final four.
It was a remarkable transformation for the three-time European champions given the turnover in personnel.
Joey Carbery and Adam Byrne, who started at fullback and on the wing respectively, made their European debuts for Leinster just this season, with centre Garry Ringrose only making his bow late last term.
Robbie Henshaw has fitted in flawlessly since his pre-season move from Irish rivals Connacht, while scrum-half Luke McGrath had only one start before this campaign.
Just over a year ago, hooker James Tracy and prop Tadhg Furlong made their first European starts while still in Leinster's academy, while Dan Leavy and Josh van der Flier have made the move from academy prospects to first-team regulars with prodigious ease.
- 'Tough dark times' -
As the province prepare for Sunday's semi-final against Clermont, Carbery, McGrath, Ringrose, Tracy, Leavy and Van der Flier are now Ireland caps –- having been nowhere near when the 2015 World Cup squad was named.
Coincidentally, it was that tournament that forced rookie Leinster coach Cullen to throw his young charges in at the deep end, with so many of the province's first-team players in Joe Schmidt's Ireland squad.
"We had to experience some tough dark times during last year’s competition so to come through, everyone has worked incredibly hard to get to this point,” Cullen said.
"But we don’t want to let ourselves down now either. We understand the challenges ahead and it’s a good gauge for how the team has progressed.”
Stuart Lancaster, sacked as England coach after the tournament hosts' first-round exit at the World Cup, has revived not only Leinster, but his own reputation, since joining the province's staff in a surprise move last September.
A new contract awaits, with both sides understandably delighted with the early stages of their partnership.
In the same week Wasps were accounted for, Leinster gave senior contracts to some of their academy starlets and renewed the deals of 13 others. It was confirmation of the good work that has been done, and a recognition of the talent at hand.
"I thought at the start of the year we looked really thin on the ground with backs when Luke (Fitzgerald) retired and Ben Te’o left and Eoin Reddan retired,” Leinster and Ireland fly-half Johnny Sexton said recently. "I was thinking ‘Jesus, we’re in a bit of trouble here’.
"Maybe it’s just that the young players have gotten their chance, and maybe we could throw the young guys in a bit more. But we badly needed it and thankfully they came through like they did."