It's the penultimate round of the URC regular season with all four provinces fighting for something.
For Connacht, it's almost do or die; they need to beat Munster on Saturday evening to stay in touch in the hunt for a play-off place.
Leinster, in fourth, host the Lions at Aviva looking to improve their seeding and stay out of Munster's reach, while eighth-placed Ulster welcome table-toppers Stormers to Belfast.
Find out all you need to know here.
ONLINE
We'll have reports and reaction on RTÉ.ie/sport and the RTÉ News app
TV
Ulster v Stormers (Friday 7.45pm) and Leinster v Lions (Saturday 5.30pm) are live on Premier Sports.
Connacht v Munster (Saturday, 7.45) is on TG4 and Premier Sports.
All games are available on URC.tv
RADIO
Connacht v Munster is live on RTÉ Radio 1's Saturday Sport.
WEATHER
Belfast expects cloudy conditions in about 10 degress on Friday night.
Dublin and Galway are set to be partly cloudy in about 12 degrees on Saturday.
Fresh of the back of a Challenge Cup semi-final win over Exeter, Ulster host URC leaders Stormers knowing a win would take them a step closer to the play-off place, which would guarantee Champions Cup rugby next season.
Depending on the outcome of Saturday's derby, they could know their fate with a round to spare.
Richie Murphy's side have lost their last two home fixtures in the championship, to Leinster and to Connacht, and have not lost three such fixtures in succession since January 2025.
The hosts will be without Stuart McCloskey and Jacob Stockdale through injury but Angus Bell is back after a foot issue.
Stormers' only loss in their last five URC matches was 24-33 to Connacht at DHL Stadium in Round 15 but they have won just twice on trips to Ireland: 16-12 over Connacht in May 2024 and 27-21 over Munster in November.
The two sides have met on five occasions with the home team on the day victorious each time.
Ulster: Michael Lowry; Werner Kok, Ethan McIlroy, Jude Postlethwaite, Zac Ward; Jack Murphy, Nathan Doak; Angus Bell, James McCormick, Tom O'Toole; Iain Henderson (capt), Charlie Irvine; Cormac Izuchukwu, Nick Timoney, Juarno Augustus.
Replacements: Tom Stewart, Eric O'Sullivan, Scott Wilson, Harry Sheridan, Bryn Ward, Conor McKee, Jake Flannery, Wilhelm De Klerk.
Stormers : Warrick Gelant; Wandisile Simelane, Dan du Plessis, Damian Willemse, Leolin Zas; Sacha Feinberg-Mngomezulu, Imad Khan; Ntuthuko Mchunu, André-Hugo Venter, Sazi Sandi; Adré Smith, Ruben van Heerden; Deon Fourie (capt), Ben-Jason Dixon, Evan Roos.
Replacements: Paul de Villiers, Oli Kebble, Zachary Porthen, Connor Evans, Hacjivah Dayimani, Keke Morabe, Stefan Ungerer, Jurie Matthee.
Referee: Andrea Piardi (FIR)
Leinster are back in URC action after last weekend's nervy win over Toulon that sees Leo Cullen's side into a ninth Champions Cup final.
They sit fourth in the table, level on points with the Lions, whose only win in four previous meetings against Leinster came at Ellis Park in 2024.
Leinster have won their last 15 matches at Aviva Stadium since Northampton beat them there in the European Cup in May 2025 but have lost three of their last five matches in the championship,
all away from home.
The visitors are on their best run ever in the URC with six wins on the bounce but their only victory in eight visits to Ireland was 38-14 over Connacht in March 2024.
Robbie Henshaw is unavailable after a head injury last weekend, while Jordan Larmour is back in full training this week and James Lowe and Tadhg Furlong continue their integration into training.
Leinster: Ciarán Frawley, Joshua Kenny, Rieko Ioane, Jamie Osborne, Jimmy O'Brien, Sam Prendergast, Luke McGrath ; Ed Byrne, John McKee, Thomas Clarkson, Brian Deeny, James Ryan (C), Max Deegan, Will Connors, James Culhane.
Replacements: Dan Sheehan, Andrew Porter, Rabah Slimani, Diarmuid Mangan, Scott Penny, Fintan Gunne, Hugh Cooney, Hugo Keenan.
Lions: Quan Horn; Erich Cronje, Henco van Wyk, Richard Kriel, Angelo Davids; Chris Smith, Morne van den Berg; SJ Kotze, PJ Botha, Asenathi Ntlabakanye; Etienne Oosthuizen, Reinhard Nothnagel; Siba Mahashe, Ruan Venter, Francke Horn (capt).
Replacements: Franco Marais, Eddie Davids, Sebastian Lombard, Darrien Landsberg, Batho Hlekani, JC Pretorius, Nico Steyn, Kelly Mpeku.
Referee: Hollie Davidson (SRU)
This is the standout game of the weekend with Connacht needing to win and hope Ulster are beaten without taking one or two bonus points to break into the top eight.
The hosts' six-game winning run in the URC ended with a 33-21 defeat at the Lions in Round 16, while they have won their last four matches at Dexcom Stadium in all competitions since Leinster beat them there, 34-23, in January.
Munster won consecutive URC matches for the first time since Round 5 in the last two rounds, while their 45-15 triumph over Benetton in Treviso in Round 15 ended a run of six consecutive defeats on the road in all competitions.
Connacht's only victory in their last six clashes with Munster was 22-9 at Dexcom Stadium on New Year’s Day 2024 but Clayton McMillan's side have lost on their last three visits to Galway.
Munster won the Thomond Park meeting 17-15 last October.
Connacht's Cathal Forde (wrist) and Matthew Victory (shoulder) will both be unavailable for the rest of the season.
The visitors are without Jack Crowley, Tadhg Beirne, Jean Kleyn, Michael Milne, Oli Jager, Tom Farrell and wing Calvin Nash with Craig Casey captaining the team from scrum-half.
A win would likely see them move into the top four with the two teams directly above, Leinster and Lions, facing off in Dublin.
Connacht: Sam Gilbert; Shane Jennings, Harry West, Bundee Aki, Shayne Bolton; Josh Ioane, Ben Murphy; Billy Bohan, Dylan Tierney-Martin, Sam Illo; Darragh Murray, Josh Murphy; Cian Prendergast (capt), Shamus Hurley-Langton, Sean Jansen.
Replacements: Eoin de Buitléar, Peter Dooley, Finlay Bealham, Joe Joyce, Paul Boyle, Matthew Devine, Jack Carty, Seán Naughton.
Munster: Mike Haley; Shane Daly, Alex Nankivell, Dan Kelly, Andrew Smith; JJ Hanrahan, Craig Casey (capt); Jeremy Loughman, Diarmuid Barron, Michael Ala'alatoa; Edwin Edogbo, Fineen Wycherley; Tom Ahern, John Hodnett, Gavin Coombes.
Replacements: Lee Barron, Josh Wycherley, Conor Bartley, Jack O’Donoghue, Brian Gleeson, Ben O’Donovan, Seán O’Brien, Alex Kendellen.
Referee: Peter Martin (IRFU)
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