Ireland coach Joe Schmidt says his side “restored a bit of self-confidence” in their 22-17 win over Wales.
After a 42-point drubbing against England a week ago, the victory in Cardiff provides Ireland with some much-needed momentum with their World Cup opener just three weeks away.
Ireland and Wales will meet again in Dublin next Saturday to conclude their World Cup preparations.
Schmidt will submit his provisional 31-man squad on Monday.
- Jacob Stockdale double gives Ireland edge over Wales
- Will Addison: England U20 star to Ireland World Cup hopeful
He will not confirm his panel until after next weekend’s final warm-up game, and Ireland will go into the encounter with a renewed spring in their step as Schmidt admitted their loss at Twickenham had “created a lot of angst for people outside the environment.”
With arguably only a handful a squad places still in the balance, a number of players strengthened their claim for a seat on the place with strong performances in Cardiff.
Prop Dave Kilcoyne was a dominant force while Andrew Porter impressed from the bench.
In the back three Andrew Conway and Will Addison, in his first game since January, both delivered eye-catching displays.
“It’s a horrible couple of days ahead,” said Schmidt.
“I know how hard these players are working and have worked for a number of years, this is the pinnacle.”
With Jacob Stockdale, Rob Kearney and Keith Earls all but certain to travel, at least one of Addison, Conway and Jordan Larmour is likely to miss out on selection despite their ability to cover numerous positions.
Addison’s accomplished performance against Wales came at full-back, although most of his Ulster appearances last season came at outside centre.
“He has such a balanced running style, he’s accomplished at kicking,” said Schmidt.
“But he’d underdone, he hasn’t played a lot. His versatility is a huge strength for him.”
Ireland’s Pool A opener is against Scotland on Yokohama on 22 September.