Dunedin - Brian O'Driscoll has said the fact Ireland have won their last 15 Tests against Italy will count for little when the teams clash for a place in the World Cup quarter-finals.
Victory for either of the European rivals at Dunedin's Otago Stadium on Sunday will all but guarantee a last eight place - something neither side managed in France four years ago.
Ireland though have already caused the upset of the tournament so far with a 15-6 Pool C win over Australia.
But they only preserved their winning streak against Italy with a nailbiting 13-11 win in Rome during the Six Nations in February secured only by a last-ditch drop-goal from fly-half Ronan O'Gara.
"They've become harder and harder to play in each match over the last four or five years," Ireland captain O'Driscoll said after coach Declan Kidney's team announcement on Friday.
"Some of the scorelines have been getting closer and closer and we really had to pull it out the bag to beat them in Rome in February," the centre added.
"It's win or bust. We felt as though we had the ability to beat Australia, but winning that game hasn't made this group any different.
Kidney sprung a surprise in his team selection by selecting 22-year-old scrum-half Conor Murray in his 1st XV ahead of the more experienced Eoin Reddan and Isaac Boss.
The other change to the team that started against Australia saw O'Gara preferred to Jonathan Sexton at outside-half.
Against the Wallabies, O'Gara had to come off the bench, playing alongside his rival as a centre, in order to seal the win after Sexton missed three out of five goalkicks.
O'Gara, on for centre Gordon D'Arcy, secured the win with two crucial penalties with Murray playing the final quarter against Australia after replacing Reddan.
Although untested as an international half-back pair, Murray and O'Gara both play for Irish provincial side Munster.
Sunday's match will be just the second time Murray has started a Test after taking the field in Ireland's opening 22-10 Pool C win over the United States and will represent just his fifth cap in all.
But O'Driscoll said Murray had the temperament to cope with such a high-stakes encounter.
"He's a confident young man who's been shown to be in his depth in these surroundings. You wouldn't know the number of Tests he has under his belt."
Italy made just one change to the team that secured a 27-10 bonus point win over the United States on Tuesday that kept their knockout phase hopes alive with fit-again full-back Andrea Masi returning in place of Luke McLean.
After the Eagles match, where the Azzurri scrum forced a penalty try, Italy coach Nick Mallett proclaimed his side had a superior front row to that of Ireland and the former South Africa boss backed up those words on Friday.
"We certainly believe we have a very strong front row, I don't regret what I said," Mallett told reporters.
"But as the Irish have quite rightly said, it's only one area and we like to think we have more to our game as well.
"We're not a one-trick pony.
"It's the right moment to say we've scored more tries than Ireland against the same (pool) opposition -- we've scored 13 they've scored 12.
"Within the team there is a genuine feeling we are getting better and if you keep getting better there must come a time when you will be equal to your opponents and I think Italy are nearing that time."
15 Rob Kearney, 14 Tommy Bowe, 13 Brian O'Driscoll (captain), 12 Gordon D'Arcy, 11 Keith Earls, 10 Ronan O'Gara, 9 Conor Murray, 8 Jamie Heaslip, 7 Sean O'Brien, 6 Stephen Ferris, 5 Paul O'Connell, 4 Donncha O'Callaghan, 3 Mike Ross, 2 Rory Best, 1 Cian Healy.
Substitutes: 16 Sean Cronin, 17 Tom Court, 18 Donnacha Ryan, 19 Denis Leamy, 20 Eoin Reddan, 21 Jonathan Sexton, 22 Andrew Trimble
15 Andrea Masi, 14 Tommaso Benvenuti, 13 Gonzalo Canale, 12 Gonzalo Garcia, 11 Mirco Bergamasco, 10 Luciano Orquera, 9 Fabio Semenzato, 8 Sergio Parisse (captain), 7 Mauro Bergamasco, 6 Alessandro Zanni, 5 Cornelius van Zyl, 4 Quintin Geldenhuys, 3 Martin Castrogiovanni, 2 Leonardo Ghiraldini, 1 Salvatore Perugini
Substitutes: 16 Fabio Ongaro, 17 Andrea Lo Cicero, 18 Marco Bortolami, 19 Paul Derbyshire, 20 Edoardo Gori, 21 Riccardo Bocchino, 22 Luke McLean