With three teams still in the race for 2014 triumph, this Saturday's Six Nations curtain closer will reveal who out of Ireland, France and England will lift this year's title.
The tournament has lived up to its billing as being the most competitive of its kind, with no other edition of the sport possessing the same level of openness.
As we head into the crunch climax, we've broken down some of those head-to-head battles that promise to have the biggest impact on which team comes out with the trophy.
Liam Williams, Wales vs. Stuart Hogg, Scotland
Wales' 29-18 loss to England on Sunday means that the reigning champions are now incapable of winning a third successive Six Nations championship, and the news of Leigh Halfpenny's dislocated shoulder was another piece of harrowing news to emerge from the disappointment.
With their first-choice full-back now out for the rest of the season, Liam Williams is likely to be deputised in the No. 15 jersey. The change impacts the Welsh kicking game dramatically but also adds an air of uncertainty in other areas.
Scotland, meanwhile, were unfortunate not to claim a shock win over the French on Saturday. Stuart Hogg was once again one of the beacons in that performance, grabbing the first try to begin the rebellion.
Scott Johnson's side may now feel that their use of the high ball will change with Hogg matched opposite a weaker aerial opponent. His incisive moves in the Scottish back line could be all the more damaging, with Williams being less of a defensive asset than the man he's likely to replace.
Louis Picamoles, France vs. Jamie Heaslip, Ireland
It was seen as a controversial decision for Philippe Saint-Andre to suspend Louis Picamoles from his squad for the trip to Scotland over the weekend, but the international staple makes his return to the line-up for Week 5, per Sky Sports.
Irrespective of the dissent that Picamoles showed toward referee Alain Rolland in Week 3, the Toulouse man's return is a massive boost for Les Bleus—and one that Jamie Heaslip may not be over the moon to hear of.
Russ Petty shows just how influential Picamoles, along with Wesley Fofana, has been for his team in recent years:
Heaslip has a tough task on his hands in attempting to emerge victorious in what promises to be an epic clash of the titans, even if Picamoles hasn't been at his attacking best during this championship.
Both players have already scored in this year's tournament, showing exactly how capable they are of inflicting pain on the opposition directly. Both figures will be looking to get their heads up from the back of the scrum on a frequent basis.
Alberto de Marchi, Italy vs. David Wilson, England
They are two of those lesser stars coming into this Six Nations due to the shoes they've been forced to fill, but Alberto de Marchi and David Wilson have shone for Italy and England, respectively, over the last seven weeks.
Both props have shown that they can be fantastic carrying assets for their teams, taking on many a foe with ball in hand and managing to come out on top, but it's perhaps the set-piece battle that is most intriguing this weekend.
England's trip to Rome will hinge on how well Stuart Lancaster's side can fare in the scrum, which is a big factor for Jacques Brunel's team. While the likes of Paul James and Cian Healy have shown Wilson up at times, the Bath tighthead will look to dominate De Marchi in his own territory on Saturday.