With just four points separating the top three teams who have already qualified for the Pro12 play-offs, no-one can yet be certain of their position in the table.
With all six games being played on Friday, the focus of attention will be in Ireland, as Glasgow Warriors face Connacht at the Sportsground in Galway, whilst Ulster welcome Cardiff Blues to Ravenhill.
A win for Ulster will put them well clear at the top of the table, anything less and they have to start looking over their shoulders at what their nearest rivals are doing.
Glasgow Warriors are the only one of the top three playing away from home, and carry the added disadvantage of having won one game less than the two team who are above them, so must go all out for a win and see what happens elsewhere to secure home advantage in the knockout stage.
The pick of the final round of this Pro12 campaign must be the repeat of last season’s final, when Leinster host Ospreys at the RDS in Dublin.
Leinster have already secured a play-off spot, the question is whether it will be home or away, whilst Ospreys must win, and other results go their way, if they are to snatch the fourth and final play-off place from Welsh neighbours, Scarlets.
Scarlets, four points clear of Ospreys and one win to the better of their rivals, have the added advantage of playing their last regular season game at home, but even so must be wary as they lost to Benetton Treviso in the reverse of this fixture earlier
in the season.
Come 22.00 on Friday, all the questions should answered.
We look at all the Round 22 action!
Friday, May 3
Zebre v Munster
(Stadio XXV Aprile – Kick-off: 19.45; 18.45 GMT)
This is the last chance this campaign for Zebre to claim that elusive first ever win in the Pro12, although they have picked up nine bonus points during the season.
Munster have won just one of their last seven Pro12 matches: 22-0 at home to Connacht on 23rd March.
The Munstermen have not won away from home in the competition in 2013 and have lost on their last two visits to Italy.
Munster won 29-3 at Thomond Park when the two sides met in round 7.
Zebre: 15 Ruggero Trevisan, 14 Giovanbattista Venditti, 13 Alberto Benettin, 12 Gonzalo Garcia, 11 Sinoti Sinoti, 10 Daniel Halangahu, 9 Tito Tebaldi, 8 Andries Van Schalkwyk, 7 Mauro Bergamasco, 6 Filippo Ferrarini, 5 Marco Bortolami (captain), 4 Josh Sole, 3 David Ryan, 2 Davide Giazzon, 1 Matias Aguero.
Replacements: 16 Andrea Mancini, 17 Luciano Leibson, 18 Andrea de Marchi, 19 Emiliano Caffini, 20 Filippo Cristiano, 21 Alberto Chillon, 22 Matteo Pratichetti, 23 Samuele Pace.
Munster: 15 Denis Hurley, 14 Ronan O’Mahony, 13 Casey Laulala, 12 Ian Keatley, 11 Johne Murphy, 10 JJ Hanrahan, 9 Cathal Sheridan, 8 Paddy Butler. 7 Sean Dougall, 6 Dave O’Callaghan, 5 Paul O’Connell (captain), 4 Billy Holland, 3 John Ryan, 2 Mike Sherry, 1 David Kilcoyne.
Replacements: 16 Damian Varley, 17 James Cronin, 18 BJ Botha, 19 Ian Nagle, 20 Johnny Holland, 21 Duncan Williams, 22 Cian Bohane, 23 Felix Jones.
Referee: Andrew McMenemy (Scotland)
Assistant Referees: Matteo Liperini, Stefano Roscini (both Italy)
TMO: Carlo Damasco (Italy)
Connacht v Glasgow Warriors
(Sportsground – Kick-off: 19.45, 18.45 GMT)
Connacht currently occupy 8th place in the Pro12 table, and are aiming to equal their best ever finish which they achieved last year.
The Irishmen have won just one of their last four games, whilst their 23-24 loss to Edinburgh at the Sportsground in December ended a six game unbeaten run against Scottish opponents in Galway.
Glasgow Warriors have already qualified for the play-offs , but will probably need to win to give themselves any chance of gaining home advantage.
The Warriors last six fixtures have all been won by the home side on the day, and they have not tasted victory on the road since beating Newport Gwent Dragons 60-3 at Rodney Parade in February.
Glasgow’s only win in Ireland since 2009 came against Leinster at RDS in September 2011.
The Warriors are unbeaten in their last three contests with Connacht, whilst they have not been victorious at the Sportsground since April 2007.
Connacht: 15 Gavin Duffy (captain), 14 Danie Poolman, 13 Eoin Griffin, 12 Brian Murphy, 11 Fetu’u Vainikolo, 10 Dan Parks, 9 Kieran Marmion, 8 Eoin McKeon, 7 Johnny O’Connor, 6 Andrew Browne, 5 Mike McCarthy, 4 Michael Swift, 3 Ronan Loughney, 2 Ethienne Reynecke, 1 Brett Wilkinson.
Replacements: 16 Adrian Flavin, 17 Rodney Ah You, 18 JP Cooney, 19 Mick Kearney, 20 John Muldoon, 21 Mata Fifita, 22 Paul O’Donohoe, 23 Miah Nikora.
Glasgow: 15 Peter Murchie, 14 Tommy Seymour, 13 Sean Lamont, 12 Peter Horne, 11 DTH Van der Merwe, 10 Ruaridh Jackson, 9 Henry Pyrgos, 8 Ryan Wilson (captain), 7 John Barclay, 6 Rob Harley, 5 Tom Ryder, 4 Tim Swinson, 3 Jon Welsh, 2 Pat MacArthur, 1 Moray Low.
Replacements: 16 Doug Hall, 17 Ryan Grant, 18 Ed Kalman, 19 James Eddie, 20 Josh Strauss, 21 Niko Matawalu, 22 Sean Maitland, 23 Stuart Hogg.
Referee: George Clancy (Ireland)
Assistant Referees: Paul Haycock, John Carvill (both Ireland)
TMO: Seamus Flannery (Ireland)
Edinburgh v Newport Gwent Dragons
(Murrayfield – Kick-off: 19.45, 18.45 GMT)
Edinburgh have slipped to successive defeats in the Pro12, to Connacht and Treviso, whilst they have won just one of their last six fixtures at Murrayfield in all competitions.
Newport Gwent Dragons’ 30-24 victory over Munster last time out ended a four match losing run in the competition.
The Dragons have not won back to back fixtures in the Pro12 since March 2012.
The Men from Gwent’s only away win this season in the tournament came on a visit to Zebre in February.
Edinburgh’s only victory over the Dragons in their last seven meetings was 22-15 at Murrayfield on 22 April 2011.
Edinburgh: 15 Greig Tonks, 14 Dougie Fife, 13 Nick de Luca, 12 Matt Scott, 11 Tim Visser, 10 Harry Leonard, 9 Greig Laidlaw (captain), 8 Netani Talei, 7 Hamish Watson, 6 Stuart McInally, 5 Grant Gilchrist, 4 Sean Cox, 3 Willem Nel, 2 Ross Ford, 1 Allan Jacobsen.
Replacements: 16 Steve Lawrie, 17 Robin Hislop, 18 Geoff Cross, 19 Perry Parker, 20 Richie McIver, 21 Sean Kennedy, 22 Piers Francis, 23 Tom Brown.
Newport Gwent Dragons: 15 Dan Evans, 14 Tom Prydie, 13 Ross Wardle, 12 Lewis Robling, 11 Tonderai Chavhanga, 10 Steffan Jones, 9 Jonathan Evans, 8 Toby Faletau, 7 Nic Cudd, 6 Dan Lydiate, 5 Rob Sidoli, 4 Andrew Coombs (captain), 3 Nathan Buck, 2 Hugh Gustafson, 1 Aaron Coundley.
Replacements: 16 Sam Parry, 17 Owen Evans, 18 Tim Ryan, 19 Adam Jones, 20 Ieuan Jones, 21 Wayne Evans, 22 Pat Leach, 23 Hallam Amos.
Referee: Marius Mitrea (Italy)
Assistant Referees: Andy Macpherson, David Changleng (both Scotland)
Leinster v Ospreys
(RDS – Kick-off: 19.45, 18.45 GMT)
Leinster must win to ensure home advantage in the play-offs.
Leinster’s only defeat in their last 14 contests in all competitions was 18-22 at home to Ulster in the Pro12 on 30th March.
The Leinstermen have lost just once to a Welsh region in any competition this season: 10-19 at the Ospreys in round 8 of the Pro12.
Ospreys also must win to give themselves any chance of taking the fourth play-off spot away from the Scarlets.
Ospreys five match unbeaten run in the Pro12 ended in the last round with their 17-35 reversal in Glasgow.
Leinster have won just one of their last seven contests with Ospreys: 15-10 at the RDS in January 2011.
Leinster: 15 Rob Kearney, 14 Andrew Conway, 13 Fergus McFadden, 12 Ian Madigan, 11 Isa Nacewa, 10 Johnny Sexton, 9 Isaac Boss, 8 Sean O’Brien, 7 Shane Jennings, 6 Rhys Ruddock, 5 Quinn Roux, 4 Leo Cullen (captain), 3 Jamie Hagan, 2 Sean Cronin, 1 Jack McGrath.
Replacements: 16 Richardt Strauss, 17 Cian Healy, 18 Michael Bent, 19 Devin Toner, 20 Dominic Ryan, 21 John Cooney, 22 Andrew Goodman, 23 Brian O’Driscoll.
Ospreys: 15 Richard Fussell, 14 Tom Habberfield, 13 Ashley Beck, 12 Ben John, 11 Ross Jones, 10 Dan Biggar, 9 Rhys Webb, 8 Joe Bearman, 7 Sam Lewis, 6 Justin Tipuric, 5 James King, 4 Alun Wyn Jones (captain), 3 Adam Jones, 2 Scott Baldwin, 1 Duncan Jones.
Replacements: 16 Dmitri Arhip, 17 Ryan Bevington, 18 Cai Griffiths, 19 Ian Evans, 20 Morgan Allen, 21 Matthew Morgan, 22 Tom Isaacs, 23 Jonathan Spratt.
Referee: Nigel Owens (Wales)
Assistant Referees: Mark Patton, Stuart Gaffikin (both Ireland)
TMO: Alan Rogan (Ireland)
Scarlets v Benetton Treviso
(Parc y Scarlets – Kick-off: 19.45, 18.45 GMT)
Scarlets’ require two match points to secure fourth place and a trip to the No.1 seeds in the play-offs.
Scarlets’ only defeat in their last nine matches in all competitions was to Leinster at the RDS on 23rd February.
The Welshmen have won their last six encounters at Parc y Scarlets since Clermont Auvergne were successful there in the European Cup in January.
Benetton Treviso have lost just one of their last six Pro12 contests: 3-28 to Ospreys in Swansea on 13th April.
The Italians have a won four, lost three record against the Welsh regions in the Pro12 this season, with all seven games being won by the home side on the day.
They are attempting to achieve only a second season’s double over a Welsh opponent emulating their success home and away over the Dragons last year.
Scarlets: 15 Liam Williams, 14 George North, 13 Jonathan Davies, 12 Scott Williams, 11 Andy Fenby, 10 Owen Williams, 9 Aled Davies, 8 Rob McCusker (captain), 7 Josh Turnbull, 6 Aaron Shingler, 5 Johan Synman, 4 George Earle, 3 Samson Lee, 2 Ken Owens, 1 Phil John.
Replacements: 16 Matthew Rees, 17 Rhodri Jones, 18 Jacobie Adriaanse, 19 Jake Ball, 20 Sione Timani, 21 Gareth Davies, 22 Rhys Priestland, 23 Gareth Maule.
Treviso: 15 Brendan Williams, 14 Christian Loamanu, 13 Michele Campagnaro, 12 Doppies La Grange, 11 Ludovico Nitoglia, 10 Kristopher Burton, 9 Edoardo Gori, 8 Robert Barbieri, 7 Alessandro Zanni, 6 Manoa Vosawai, 5 Antonio Pavanello (captain), 4 Francesco Minto, 3 Bees Roux, 2 Giovanni Maistri, 1 Michele Rizzo.
Replacements: 16 Enrico Ceccato, 17 Alberto De Marchi, 18 Ignacio Fernandez-Rouyet, 19 Valerio Bernabò, 20 Simone Favaro, 21 Fabio Semenzato, 22 James Ambrosini, 23 Luca Morisi.
Referee: Dudley Phillips (Ireland)
Assistant Referees: Neil Hennessy, Tim Hayes (both Wales)
TMO: Huw Lewis (Wales)
Ulster v Cardiff Blues
(Ravenhill – Kick-off: 19.45, 18.45 GMT)
Ulster require three more match points to ensure that they finish at the top of the table.
The Ulsterman have won their last three Pro12 matches and have lost just once at Ravenhill in the competition all season: 12-16 to Ospreys in February.
Cardiff Blues have secured just six league points from their last half a dozen Pro12 encounters and have lost their last three away games in the competition.
The Blues only two victories over Irish provinces this season have strangely both been away from home – in Connacht in round one and Munster round 13.
Cardiff Blues’ only victory over Ulster in their last five fixtures was 21-14 at the Arms Park on 17th February 2012.
Ulster: 15 Jared Payne, 14 Andrew Trimble, 13 Darren Cave, 12 Stuart Olding, 11 Tommy Bowe, 10 Ruan Pienaar, 9 Paul Marshall, 8 Nick Williams, 7 Chris Henry, 6 Robbie Diack, 5 Iain Henderson, 4 Johann Muller (captain), 3 John Afoa, 2 Rory Best, 1 Callum Black.
Replacements: 16 Nigel Brady, 17 Tom Court, 18 Declan Fitzpatrick, 19 Dan Tuohy, 20 Sean Doyle, 21 Paddy Jackson, 22 Michael Allen, 23 Peter Nelson.
Cardiff Blues: 15 Dan Fish, 14 Alex Cuthbert, 13 Gavin Evans (captain), 12 Dafydd Hewitt, 11 Harry Robinson, 10 Rhys Patchell, 9 Lewis Jones, 8 Michael Paterson, 7 Josh Navidi, 6 Luke Hamilton, 5 Lou Reed, 4 Bradley Davies, 3 Scott Andrews, 2 Kristian Dacey, 1 Taufa’ao Filise.
Replacements: 16 Marc Breeze, 17 Thomas Davies, 18 Campese Ma’afu, 19 Teofilo Paulo, 20 Macauley Cook, 21 Liam Davies, 22 Ceri Sweeney, 23 Tom James.
Referee: Neil Paterson (Scotland)
Assistant Referees: Sean Gallagher, Nigel Correll (both Ireland)
TMO: Seamus McDowell (Ireland)
Farewell to a man who has been a fans favourite for many years, Edinburgh’s prop Allan Jacobsen – also known as ‘Chunk’. He has been a fantastic servant to Scottish rugby and tonight will anchor the scrum for Edinburgh for the final time. Chunk’s career with Edinburgh spans a long 16 years in which time he has appeared 285 times for the team based in the capital. He can also boast of 65 international caps for Scotland. Go well BIG MAN, all the best for your future.
Final Table (after Twenty Two rounds completed)