Success by seven points will be enough for Wales to finish top of the standings if England don't score two more tries at the Millennium Stadium - a feat that scarcely seemed possible after they were blown away in the first 45 minutes of their opening clash with Ireland six weeks ago.
For England, a 'W' of any sorts is all that's required as Stuart Lancaster's troops go in search of a holy grail that has eluded them ever since Martin Johnson and co stormed to victory at Lansdowne Road back in 2003.
That demoltion of the Irish in Dublin preceded a World Cup triumph the very same year and, while there is no global gathering immediately ahead this time around, the presence of the Lions' 125th anniversary adventure in Australia adds an extra carrot in 2013.
Lions head coach Warren Gatland is undoubtedly his own man, but an English win across the River Severn and a Grand Slam to boot would surely lead to calls for a heavy Red Rose representation Down Under.
Likewise, a Welsh win would have the papers calling for the Dragons to dominate the selection announcement at the end of April despite a number of high-profile names being written off following eight straight defeats between June and early February.
One of the biggest names to have his star so publicly dimmed in the press during Wales' dismal run was former skipper Sam Warburton. Struggling for form before suffering the shoulder injury that forced him out of the win in Paris and then out of the starting XV in Italy, Warburton went from likely Lions leader to potential selection casualty in a matter of weeks.
But a man-of-the-match display in the 28-18 win over Scotland suddenly has everyone purring again and his head-to-head battle with Chris Robshaw could have a huge impact on more than just who comes out on top on Saturday.
Robshaw has been outstanding for England since taking over the captaincy 13 months ago, with the question marks over his decision making that arose in the defeat to South Africa largely forgotten about since the historic hammering of the All Blacks seven days later. The Harlequins back rower has to be in the running for the Lions leadership and seeing off Warburton and Wales would do his chances of receiving the ultimate honour no harm at all.
But it's not just at the breakdown where Lions battles will be played out in Cardiff, with equally exciting individual match ups in midfield, out wide and up front. Watching Jamie Roberts and Jonathan Davies clash with Brad Barritt and Manu Tuilagi is mouth-watering enough but what about Mike Phillips versus Ben Youngs or Danny Care at scrum-half or Geoff Parling and Joe Launchbury against Alun Wyn Jones and Ian Evans in the second row?
Then there's the contest at scrum time where Dan Cole and Adam Jones will look to press their claims for the Lions' starting tight-head berth; Richard Hibbard will be desperate to get one over on Tom Youngs at hooker and Gethin Jenkins will aim to prove that experience over-rides the enthusiasm of youth against Joe Marler..
Gatland will unsurprisingly be in Cardiff for what promises to be real cracker but he'll also have eyes and ears in Rome and Paris as Ireland and Scotland look to finish on a high.
The 'Super Saturday' format means the Lions boss can only attend one fixture in person but he'll be studying video footage of Ireland's early game against Italy and Scotland's evening climax against the French. And while the Championship may not be on the line at either the Stadio Olimpico or the Stade de France, there's still plenty at stake given what lies just around the corner.
Ireland's campaign began so brightly when they dismantled champions Wales in their own backyard for the first part of a pulsating encounter but things have soured since then. Injuries have undoubtedly taken their toll, with Declan Kidney and co enduring an absentee list nearly as lengthy as the one suffered by the Wallabies in 2012.
Defeats to England and Scotland and a draw with France wasn't the follow up the Irish were looking for after the celebrations in Cardiff but there have been some promising individual performances along the way. Sean O'Brien has been hugely powerful with ball in hand; Donnacha Ryan has established himself as a real force in the second row and Luke Marshall has produced some eye-catching running lines in his two Tests to date.
Donnacha Ryan has come to the fore in a frustrating campaign for Ireland
Big name Lions may still be missing in the shape of Paul O'Conell, Tommy Bowe and Stephen Ferris, but triple tourist Brian O'Driscoll is still being heavily tipped for a southern hemisphere swansong and the likes of Rory Best and Cian Healy are heavy tour favourites, while Jamie Heaslip and Rob Kearny appear to be finding their form.
No doubt Gatland will have his eyes on Jonathan Sexton at fly-half and Craig Gilroy on the wing as both men make their comebacks from injury but the best way for potential Irish Lions to make a statement is to finish strongly as a side.
The same goes for the Scots, who had hoped to be challenging for the Championship this week before Wales ended that dream in Edinburgh.
Scott Johnson's men showed plenty of promise in the wins over Italy and Ireland and, although they weren't at their best last time out, victory in Paris would suggest that they have really come of age. It will also perhaps persuade Gatland that some of the young guard can make the step up for Britain and Ireland's elite, while the more established players who have missed out on past Lions adventures may be ready to make amends in 2013.
Stuart Hogg has received so much praise since the opening fixture in England that critics are convinced he has already done enough to earn his place in Gatland's squad but what about the others around him? Refreshingly Gatland seems to have a number of realistic Scottish options. While Scotland might be struggling for 'nailed on certainties', there are no shortage of contenders coming from a country that has celebrated fewer Lions than they would have liked in modern times.
Since Alan Tait, Gregor Townsend, Tom Smith, Dodie Weir and Rob Wainwright played their part on the victorious tour of South Africa 16 years ago, only eight more Scots have earned selection in an original Lions party across the three adventures that have followed. Five more may have been called up as replacements before or during those tours but Scotland were definitely under represented in 2001, 2005 and 2009.
Prior to the start of this year's tournament, few were predicting a move away from that pattern, but fast forward a month-and-a-half and there's a real chance that could change come April. Skipper Kelly Brown and back row partner Johnnie Beattie have been hugely impressive to date; Richie Gray remains one of the leading locks despite a hamstring injury ruling him out for eight weeks; Ryan Grant has emerged as a genuine prop prospect alongside 2009 Lion Euan Murray; hooker Ross Ford has hit some form after being dropped early on and Jim Hamilton gave a timely reminder of his battling qualities with a man of the match display against Ireland.
Johnnie Beattie has been a standout performer for Scotland so far
Greig Laidlaw has enhanced his claims week-on-week and his ability to play both scrum-half and fly-half may appeal to Gatland; Matt Scott has stepped up in the centres and Tim Visser and Sean Maitland have shown glimpses of their abilities out wide in their debut Championship.
Gatland clearly has his work cut out when it comes to picking a 30-something squad for the summer but he and tour manager Andy Irvine will be hoping that - regardless of results, of Grand Slam glories, Championship crowns or fitting finales - this weekend at least provides some more clarity when it comes to who should be heading to Hong Kong and Oz.