With the Irish clinging to their Six Nations crown by their fingernails, it is win or bust for the visitors against England at Twickenham.
A draw and a loss leaves Joe Schmidt's side on one point while England, the favourites with Betbright, are riding high at the top after two somewhat expected victories.
The English can put the nail in Ireland's coffin this weekend when they make their bow on home soil, thus ending their visitors' recent stranglehold on the trophy. Alternatively, a different result would throw this Championship wide open.
Ireland enter Twickenham as the underdogs, which they won't mind one bit, whilst any team-talk has been done by England's head coach Eddie Jones. His comments about Jonathan Sexton's health will no doubt have stirred the pot while he also hinted the playmaker will be targeted.
It wouldn't be England versus Ireland without plenty of needle going onto the field and don't be surprised if things spill over early on, with history telling us both captains have previous against each other. With so much on the line, referee Romain Poite will be kept busy.
Managing the pressure is going to be the difference at Twickenham and it's no disservice to Scotland and Italy that Saturday will be the true test of this English side will come. Will the George Ford-Owen Farrell combination pass another test? That is a concern for England after what was a comfortable game in Rome. Make no mistake, debutant Stuart McCloskey, Robbie Henshaw and of course CJ Stander will test that channel.
England though will do the same in terms of targeting fly-half Sexton and there lies a major tipping point of this contest and an expectancy that it won't be pretty on Saturday. It rarely is between England and Ireland but what it lacks in tries, it more than makes up for in tension. Let the battle commence.
Players to watch:
For England: After plenty of backing from the media, on Thursday the vast majority of the English public got their wish as Maro Itoje was handed his first international start for the senior team. The all-Saracens second-row combination of Itoje and George Kruis should give Ireland plenty of headaches, with many expecting this to be the start of a long and prosperous career for the former England U20 captain. A unique talent with a mature head on young shoulders and if the Irish haven't done their homework already, they'll sure know about him on Saturday.
For Ireland: Another fresh face is our pick for the Irish and that is Stuart McCloskey. The 23-year-old has been impressing week in week out for Ulster and we're looking forward to seeing how he fares at the next level. A powerful ball carrier with good hands, his start also means Robbie Henshaw moves out to arguably his stronger position of outside centre, which could bring double reward for Schmidt in London. Also keep an eye on fly-half Jonathan Sexton after England coach Jones' comments, which will no doubt fire up the playmaker.
Head-to-head: They have come to blows in the past in club colours and there's no reason to think things might boil over again between opposing hookers and captains Dylan Hartley and Rory Best. Expect no quarter to be given nor asked in a mouth-watering clash up front. It may get rather spicy.
2015: England won 21-13 in London
2015: Ireland won 19-9 in Dublin
2014: England won 13-10 in London
2013: England won 12-6 in Dublin
2012: England won 30-9 in London
2011: England won 20-9 in Dublin
2011: Ireland won 24-8 in Dublin
2010: Ireland won 20-16 in London
2009: Ireland won 14-13 in Dublin
2008: England won 33-10 in London
Prediction: Both benches are strong and will play a role on Saturday but we think the hosts just have the edge on the whole. England by 3.
England: 15 Mike Brown, 14 Jack Nowell, 13 Jonathan Joseph, 12 Owen Farrell, 11 Anthony Watson, 10 George Ford, 9 Ben Youngs, 8 Billy Vunipola, 7 James Haskell, 6 Chris Robshaw, 5 George Kruis, 4 Maro Itoje, 3 Dan Cole, 2 Dylan Hartley (c), 1 Joe Marler
Replacements: 16 Jamie George, 17 Mako Vunipola, 18 Paul Hill, 19 Courtney Lawes, 20 Jack Clifford, 21 Danny Care, 22 Elliot Daly, 23 Alex Goode
Ireland: 15 Rob Kearney, 14 Andrew Trimble, 13 Robbie Henshaw, 12 Stuart McCloskey, 11 Keith Earls, 10 Jonathan Sexton, 9 Conor Murray, 8 Jamie Heaslip, 7 Josh van der Flier, 6 CJ Stander, 5 Devin Toner, 4 Donnacha Ryan, 3 Mike Ross, 2 Rory Best, 1 Jack McGrath
Replacements: 16 Richardt Strauss, 17 Cian Healy, 18 Nathan White, 19 Ultan Dillane, 20 Rhys Ruddock, 21 Eoin Reddan, 22 Ian Madigan, 23 Simon Zebo
Date: Saturday, February 27
Kick-off: 16:50 GMT
Referee: Romain Poite (France)
Assistant Referees: Nigel Owens (Wales), Alexandre Ruiz (France)
TMO: Shaun Veldsman (South Africa)