Five into four doesn't go, meaning the battle to make the Play-Offs and secure the advantageous home tie is still up for grabs between Glasgow Warriors, Leinster, Connacht, Ulster or Scarlets.
Defending champions Glasgow Warriors and Connacht are currently in pole position in first and second place respectively in the table and they will go head to head at the Sportsground for one of the home Play-Offs places with the winner guaranteed to take it.
The form book would put the Warriors as the favourites with the Scottish side appearing to time their run to top form to perfection.
They have won their last nine Guinness PRO12 encounters, including their biggest ever competition victory at home to Zebre last weekend which saw them top the table for the first time this season.
Connacht meanwhile have lost three of their last four matches in all competitions and have come out on the wrong side of the scoreboard in their last eight fixtures against Glasgow Warriors.
However with their only defeat at The Sportsground this season in any tournament coming against Ulster in the Guinness PRO12 on December 26, expect the Irishmen to put up plenty of fight.
And in winger Matt Healy, currently the Guinness PRO12's top try scorer with nine, they have someone capable of causing damage to the Glasgow defence.
The loser of the match will of course be looking over their shoulders to see how Leinster are faring against Benetton Treviso with the Irish province also looking to snatch a home Play-Off for the third year in a row.
Currently third in the table, a bonus point win should be enough to do just that - and the Leinstermen will be favourites to do so at the RDA Arena.
Leinster's last six matches have all been won by the home side on the day while they are the only side with a perfect played ten, won ten home record this season.
It could also be a special day for Jamie Heaslip who needs to cross the whitewash twice to bring up the 25-try milestone while Johnny Sexton will be aiming to keep the pressure on Munster's Johnny Holland in the race to be the best Guinness PRO12 kicker.
Treviso should not be written off however after they climbed above Zebre for the first time this season with a last-minute victory over Connacht in round 21.
Just a point separates Treviso and Zebre in the race for Italian Champions Cup qualification - but Treviso will need to dig deep with their only previous victory over Leinster coming in their very first meeting back in September 2010.
Ulster and Scarlets are the other two teams in the mix for the Play-Offs although only the former can still claim a home tie.
The Irish province travel to Ospreys with just one defeat during the last five rounds with a maximum-point win guaranteeing them a Play-Off place for the fourth successive year.
With eight tries, Craig Gilroy is just one score behind Healy in the race to be top try scorer while Paddy Jackson - who is currently second in the race for the Rhino Golden Boot behind Edinburgh's Jason Tovey- needs just four more points to break the 500 point barrier.
Ospreys require a victory to give themselves any chance of a Champions Cup spot next season, and while that may still not be enough, they will be buoyed by the fact they have won their last three matches, all with maximum points. The match could also see flanker James King make his 100th Ospreys appearance while Dan Evans is one try away from 25 career PRO12 tries.
Scarlets, who are already assured to be the highest Welsh finishers, meanwhile face Munster on Saturday having ended their two-game losing streak against Newport Gwent Dragons on Judgement Day although their only previous victory in Limerick was back in September 2003.
Munster have plenty to play for though too, with two points securing Champions Cup rugby in 2016/2017.
Should Munster not pick up a point in round 22, Ospreys or Edinburgh could still mathematically overtake the Irish side in the race for a place in Europe's top tier of competition next season.
Eighth-placed Edinburgh are at home to Cardiff Blues in a match where they must pick up a maximum point win to keep their faint hopes alive.
The Scotsmen have lost just once at BT Murrayfield in any tournament since November but they have been defeated in their last two Guinness PRO12 matches against Leinster and Munster.
Cardiff Blues came out on the wrong side in their Judgement Day game against Ospreys last time out although their only defeat in their last six fixtures with Edinburgh was in the equivalent fixture at BT Murrayfield in round 8 last season.
The day's final game will see Zebre and Newport Gwent Dragons lock horns in Italy.
Both have struggled for form at the business end of the season with Zebre having not won in the Guinness Pro12 since January 3 while the Dragons' only victory in their last 11 matches in all competitions was their Challenge Cup quarter final win over Gloucester on April 9.
To buy tickets for the Guinness PRO12 Grand Final click here. Also follow us on Facebook, join the conversation on Twitter, sign up to our YouTube channel for extensive match highlights and sign up for our newsletter for regular updates on the Guinness PRO12.
63x46.png){kind=logo}