Ireland may have won in Wales for the first time since 2009 last weekend, but Declan Kidney's men face arguably an even bigger challenge against Stuart Lancaster's highly-rated England in Dublin on Sunday.
Ireland have gained momentum thanks to their morale-boosting victory over Argentina in the autumn which went some way to helping secure their 30-22 success in Cardiff. And Ireland were rampant in the first half as the visitors punished numerous Wales mistakes, leading 23-3 at the break.
However, Kidney's side almost fatally released their grip on Welsh throats in the second half. Ireland won't be able to do that against the Red Rose and must replicate that first-half performance in Cardiff over 80 minutes on Sunday if Jamie Heaslip and co are to beat a side which are brimming with confidence following New Zealand and Scotland wins.
Perhaps the most intriguing battle will be between Ireland's back-line. How much did last weekend's victory take out of Gordon D'Arcy and Brian O'Driscoll? D'Arcy is a major doubt with a dead leg and the home side can ill-afford to lose him with the daunting prospect of facing Manu Tulagi and Billy Twelvetrees (or Brad Barritt).
One to watch: Mike Ross
Mike Ross left the Millennium Stadium pitch after 55 minutes with cramp but has taken part in training since Tuesday. The Leinster prop was a big force against Wales as he overpowered Gethin Jenkins. Ross's withdrawal after 36 minutes was a turning point in last year's 30-9 loss at Twickenham, highlighting his influence. Such is the respect Lancaster has for Ross, there's talk of the Red Rose targeting the Ireland star on Sunday. He will be vital to the success of Ireland's scrum.