After a weekend that saw leaders Ospreys fall to their first defeat of the season, and Italian outfit Benetton Treviso gain their first ever try bonus point, the top four teams in the Pro12 stayed the same with Ospreys, Munster, Leinster and Cardiff Blues currently occupying the play-off zone spots.

Two of those teams, Leinster and Munster, face each other in what must be the biggest game of the weekend, if only in crowd size, in the Round Eight clash in Dublin.

Fortune must favour the home team, who have not lost any game they've played at the venue since 2006, however the visitors, reigning champions Munster, have been successful in their last six encounters against other Irish Provinces.

With World Cup stars returning to action, this promises to be the tie of the round.

In the only other game on Friday, fourth placed Cardiff Blues will be looking to consolidate that play-off spot when they travel to Newport Gwent Dragons, although their hosts currently have an excellent record at Rodney Parade where they will be celebrating the opening of their new stand.

The remaining Round Eight games all take place on Saturday, with two games in Italy in the afternoon, both involving Scottish opposition. Aironi host Glasgow Warriors, whilst Benetton Treviso welcome Edinburgh. After the impressive victory Treviso recorded last round against the Dragons, Edinburgh cannot be looking forward to the journey, especially as each side won its respective home game last season. Glasgow Warriors on the other hand, with a won four, lost three record so far this season, will be looking to improve on the margin of victory they achieved on their last trip to Aironi when they won by a single point.

The remaining two games are an all-Welsh and an all-Irish affair, Ospreys facing Scarlets and Ulster hosting Connacht. Victory over the table topping Ospreys at the Liberty Stadium will be a tough ask for Scarlets who have only won there once before, in 2007.

Connacht's record against Ulster, especially in the Province, is not good, however their hosts lost their unbeaten record to Benetton Treviso last time out at Ravenhill. Ulster and Ospreys are both still searching for that elusive 100th competition victory.

We look at all the Round Eight games!

Friday, November 4:

Leinster v Munster
(Aviva Stadium - 20.00; 20.00 GMT)

Leinster's only defeat in their last six Pro12 matches was 19-23 at home to Glasgow Warriors on 17 September. Leinster have won their last nine matches in all competitions at Aviva Stadium/Lansdowne Road since Munster beat them there, in the 2006 European Cup semifinal.

Munster's two game losing run ended with their 18-6 defeat of Aironi on Friday. The Munstermen's only previous win at this venue in this tournament was when they beat Ulster 15-9 in the semifinal on 8 December 2001. Munster have won their last six encounters with fellow Irish provinces.

Munster won two of the three meetings with Leinster last season including the final at Thomond Park on 28 May.

Munster's only win on Leinster soil since 2006 was at the RDS in September 2008.

Teams:

Leinster: 15 Rob Kearney, 14 Isa Nacewa, 13 Fergus McFadden, 12 Gordon D'Arcy, 11 Luke Fitzgerald, 10 Jonathan Sexton, 9 Isaac Boss, 8 Jamie Heaslip, 7 Shane Jennings, 6 Sean O'Brien, 5 Devin Toner, 4 Leo Cullen (captain), 3 Mike Ross, 2 Richardt Strauss, 1 Cian Healy.
Replacements: 16 Sean Cronin, 17 Heinke van der Merwe, 18 Jamie Hagan, 19 Kevin McLaughlin, 20 Rhys Ruddock, 21 Eoin Reddan, 22 Ian Madigan, 23 Eoin O'Malley.

Munster: 15 Johne Murphy, 14 Doug Howlett, 13 Will Chambers, 12 Lifeimi Mafi, 11 Keith Earls, 10 Ronan O'Gara, 9 Conor Murray, 8 Denis Leamy, 7 Niall Ronan, 6 Donnacha Ryan, 5 Paul O'Connell (captain), 4 Donncha O'Callaghan, 3 BJ Botha, 2 Damien Varley, 1 Wian du Preez.
Replacements: 16 Denis Fogarty, 17 Marcus Horan, 18 John Hayes, 19 Peter O'Mahony, 20 James Coughlan, 21 Tomas O'Leary, 22 Ian Keatley, 23 Danny Barnes.

Referee: Pascal Gauzere (France)
Assistant Referees: David Wilkinson, Simon McDowell (both Ireland)
TMO: Marshall Kilgore (Ireland)

Newport Gwent Dragons v Cardiff Blues
(Rodney Parade - 19.05; 19.05 GMT)

Newport Gwent Dragons' only victory in their last four Pro12 matches was 22-9 at home to Ulster in round five. Dragons have won five of their last six games at Rodney Parade in the tournament.

Cardiff Blues have won back to back Pro12 matches, both away from home at Aironi and Connacht, but are winless in five encounters with fellow Welsh regions in 2011.

The Men from Gwent ended an eight game losing streak against the Blues when the two sides last met at Rodney Parade in April.

Teams:

Newport Gwent Dragons: 15 Martyn Thomas, 14 Tonderai Chavhanga, 13 Adam Hughes, 12 Ashley Smith (captain), 11 Aled Brew, 10 Jason Tovey, 9 Wayne Evans, 8 Lewis Evans, 7 Gavin Thomas, 6 Andrew Coombs, 5 Scott Morgan, 4 Adam Jones, 3 Dan Way, 2 Rhys Buckley, 1 Phil Price.
Replacements: 16 Lloyd Burns, 17 Nathan Williams, 18 Nathan Buck, 19 Rob Sidoli, 20 Tom Brown, 21 Joe Bedford, 22 Lewis Robling, 23 Steffan Jones.

Cardiff Blues: 15 Chris Czekaj, 14 Alex Cuthbert, 13 Casey Laulala, 12 Jamie Roberts, 11 Tom James, 10 Dan Parks, 9 Richie Rees, 8 Xavier Rush, 7 Josh Navidi, 6 Michael Paterson, 5 James Down, 4 Bradley Davies, 3 Taufa'ao Filise, 2 T Rhys Thomas (captain), 1 Gethin Jenkins.
Replacements: 16 Ryan Tyrrell, 17 John Yapp/Sam Hobbs, 18 Scott Andrews, 19 Paul Tito, 20 Maama Molitika, 21 Lloyd Williams, 22 Ceri Sweeney, 23 Gavin Evans.

Referee: Nigel Owens (WRU)
Assistant Referees: Gwyn Morris, Wayne Davies (both WRU)
TMO: Gareth Simmonds (WRU)

Saturday, November 5:

Aironi v Glasgow Warriors
(Stadio Zaffanella - 14.30; 13.30 GMT)

Aironi have slipped to three straight defeats in the Pro12 since their 25-19 victory over Edinburgh at Stadio Zaffanella on 24 September - their only previous victory against a Scottish opponent.

Glasgow Warriors have won their last three matches in the tournament but have not won four in a row in the competition since the tail end of the 2009/10 season. The Warriors have lost their last two matches against Italian opposition.

Glasgow won both encounters with Aironi last season but the match in Italy was by the narrowest of margins, 17-16.

Teams:

Aironi: TBC

Glasgow Warriors: 15 Peter Murchie, 14 Federico Aramburu, 13 Alex Dunbar, 12 Troy Nathan, 11 Tommy Seymour, 10 Duncan Weir, 9 Chris Cusiter, 8 Johnnie Beattie, 7 John Barclay, 6 James Eddie, 5 Al Kellock (captain), 4 Richie Gray, 3 Ed Kalman, 2 Dougie Hall, 1 Ryan Grant.
Replacements: 16 Finlay Gillies, 17 Gordon Reid, 18 Mike Cusack, 19 Rob Verbakel, 20 Ryan Wilson, 21 Henry Pyrgos, 22 Graeme Morrison, 23 Stuart Hogg.

Referee: Dudley Phillips (Ireland)
Assistant Referees: Marius Mitrea, Stefano Roscini (both Italy)

Benetton Treviso v Edinburgh
(Stadio Monigo - 15.00; 14.00 GMT)

Benetton Treviso's run of four consecutive Pro12 wins has seen them rise to 5th place in the table - their highest ever placing. Last Saturday's 50-24 bonus point win over Dragons saw them more than double their record for tries in a single game with seven.

Edinburgh Rugby have slipped to successive Pro12 defeats and have won just once on their travels in any competition since December 2009: 10-9 at Aironi on 2 October 2010.

Each side easily won its respective home game when the two sides met last season.

Teams:

Benetton Treviso: TBC

Edinburgh: TBC

Referee: Andy Macpherson (Scotland)
Assistant Referees: Alan Falzone, Stefano Marama (both Italy)

Ospreys v Scarlets
(Liberty Stadium - 18.30; 18.30 GMT)

Ospreys perfect start to the new Pro12 season was spoiled by Glasgow at Firhill on Friday. Ospreys have now lost their last three games in all competitions, but have been defeated just once at Liberty Stadium in their last dozen matches in this tournament.

Scarlets have won their last four matches in all competitions, although their only triumph away from home in this tournament since January was 37-29 at Glasgow on 22 April.

Ospreys have won their last six encounters against Scarlets, whilst Scarlets only previous victory at Liberty Stadium came in September 2007.

Teams:

Ospreys: TBC

Scarlets: TBC

Referee: Mathieu Raynal (France)
Assistant Referees: Neil Hennessy, Jon Mason (both WRU)
TMO: Tony Rowlands (WRU)

Ulster v Connacht
(Ravenhill - 17.35; 17.35 GMT)

Ulster have slipped to four successive Pro12 defeats since they beat Cardiff Blues at Ravenhill on 16 September.

The Ulstermen's nine game home winning run ended last time out at Ravenhill with the visit of Benetton Treviso. Ulster have won just one of their last seven encounters with fellow Irish provinces.

Connacht have lost their last three Pro12 matches and have won only once on the road in the competition since September 2010: 11-9 at Treviso on 3 September 2011. Connacht's solitary victory in their last 16 matches against fellow Irish provinces was 27-13 over Leinster at the Sportsground on 21 April 2010.

Connacht have won just once away from home in Ireland in the history of this competition: 26-23 against Leinster at Donnybrook in September 2002. Connacht's only win over Ulster since 2003 was 22-12 in Galway on New Year's Eve 2005, whilst Connacht have not won in Belfast since 1960.

Teams:

Ulster: TBC

Connacht: TBC

Referee: John Lacey (Ireland)
Assistant Referees: Paul Haycock, Brian MacNeice (both Ireland)
TMO: Tony Redmond (Ireland)