Round Four of the Pro 12 kicks-off on Friday with the champions and current leaders, Munster, travelling to the team they deposed from the top of the table, Cardiff Blues.

Munster's defensive record is such that they haven't conceded a try so far this season, however Blues possess two of Pro 12's top try scorers in Sam Hobbs and Tom James, who have scored three apiece so far, so perhaps this time the Munster tryline may be breached.

Also on Friday, Newport Gwent Dragons travel to Galway to face Connacht, a team they haven't beaten on their own soil since the first visit in 2004, whilst Glasgow Warriors host Benetton Treviso.

The Italian outfit have not yet won outside of Italy in the Pro 12, and Glasgow, having won in Dublin last weekend, must be looking to consolidate on that performance.

The Scotland v Italy theme continues on Saturday, but this time the action moves to Italy when Aironi welcome an Edinburgh team who will remember that they lost on their last visit to that country; 31-6 to Benetton Treviso in May.

Scarlets and Leinster are also in action on Saturday. Neither side has had a very good start to the season, both with a won
1 lost 2 record, and are sitting the wrong side of the playoff zone, so will be looking for a win to get their campaign back
on track.

The round wraps up on Sunday, with Pro 12's other two unbeaten teams, Ospreys and Ulster, in action at the Liberty Stadium. Both teams have been building up impressive records from the end of last season, however if home advantage is anything to go by, Ospreys have the edge on that having won five of the seven encounters at Liberty Stadium.

We look at all the Round Four action!

Friday, September 23:

Cardiff Blues v Munster
(Cardiff City Stadium - 19.05)

Cardiff Blues lost their place at the top of the PRO 12 table following their 3-20 defeat at Ulster. The Blues have won just one of their last four matches against Irish provinces.

Defending champions Munster returned to the top of the table and stretched their record breaking winning run to 13
matches against Scarlets on Saturday.

The Munstermen have conceded only one try in their last six matches and have now gone 322 minutes without having their defences breached. Munster themselves hold the record for the longest spell without conceding a try, with a 371 minute sequence in the 2004/05 season.

Munster achieved the league double over the Blues last season, whilst the Blues have never won in five previous visits to
Thomond Park.

Teams:

Cardiff Blues: 15 Dan Fish, 14 Alex Cuthbert, 13 Gavin Evans, 12 Dafydd Hewitt, 11 Richard Mustoe, 10 Ceri Sweeney, 9 Richie Rees, 8 Andries Pretorius, 7 Maama Molitika, 6 Michael Paterson, 5 Deiniol Jones, 4 Paul Tito (captain), 3 Scott Andrews, 2 T Rhys Thomas, 1 Sam Hobbs.
Replacements: 16 Rhys Williams, 17 Nathan Trevett, 18 Ryan Harford, 19 Xavier Rush, 20 Thomas Young, 21 Lewis Jones, 22 Rhys Patchell, 23 Casey Laulala.

Musnter: 15 Johne Murphy, 14 Doug Howlett, 13 Danny Barnes, 12 Lifiemi Mafi, 11 Denis Hurley, 10 Ian Keatley, 9 Duncan Williams, 8 James Coughlan, 7 Tommy O'Donnell, 6 Peter O'Mahony (captain), 5 Mick O'Driscoll, 4 Billy Holland, 3 Stephen Archer , 2 Mike Sherry, 1 Wian du Preez.
Replacements: 16 Denis Fogarty, 17 John Ryan, 18 John Hayes, 19 Dave Foley, 20 Niall Ronan, 21 Peter Stringer, 22 Scott Deasy, 23 Tom Gleeson.

Referee: David Wilkinson
Assistant Referees: David Jones, Huw Griffiths
TMO: Gareth Simmonds

Connacht v Dragons
(Sportsground - 19.30)

Connacht's winning start to the season came to a halt at Edinburgh last weekend, whilst the Irishmen's only defeat at the Sportsground in their last eight matches in all competitions was 12-26 to Cardiff Blues on 15 April.

Newport Gwent Dragons move off the basement in the table courtesy of their 23-14 home win against Aironi on Sunday.

Dragons have not won on the road since their visit to Aironi on 20 February. The Men from Gwent have lost their last six encounters with Irish opponents.

The last six encounters between the two teams have all been won by the home side on the day, whilst Dragons' only
previous victory on Connacht soil came on their very first visit in May 2004.

Teams:

Connacht: 15 Gavin Duffy (captain), 14 Brian Tuohy, 13 Eoin Griffin, 12 Henry Fa'afili, 11 Tiernan O'Halloran, 10 Niall O'Connor, 9 Frank Murphy, 8 Ray Ofisa, 7 Johnny O'Connor, 6 John Muldoon, 5 Mike McCarthy, 4 Dave Gannon, 3 Rodney Ah You, 2 Ethienne Reynecke, 1 Brett Wilkinson.
Replacements: 16 Adrian Flavin, 17 Ronan Loughney, 18 Dylan Rogers, 19 Mick Kearney, 20 TJ Anderson, 21 Paul O'Donohoe, 22 Mathew Jarvis, 23 James Loxton.

Dragons: 15 Martyn Thomas, 14 Matthew Pewtner, 13 Pat Leach, 12 Ashley Smith, 11 Geraint O'Driscoll, 10 Jason Tovey, 9 Joe Bedford, 8 Andrew Coombs, 7 Gavin Thomas, 6 Lewis Evans, 5 Rob Sidoli, 4 Adam Jones, 3 Dan Way, 2 Tom Willis (captain), 1 Nathan Williams.
Replacements: 16 Rhys Buckley, 17 Phil Price, 18 Nathan Buck, 19 Darren Waters, 20 Jevon Groves, 21 Wayne Evans, 22 Tom Riley, 23 Matthew Jones.

Referee: Leighton Hodges
Assistant Referees: Leo Colgan, Olly Hodges

Glasgow Warriors v Treviso
(Firhill Stadium - 19.30)

Glasgow Warriors snapped their five game losing sequence with their magnificent 23-19 victory to end Leinster's
incredible 29 match home winning run last Saturday. The Warriors have slipped to defeat in their last three encounters at
Firhill.

Benetton Treviso have begun the season with three successive defeats. Treviso's only away victory in the tournament so far came at fellow Italian outfit Aironi in December. Treviso have not won in Scotland since their visit to Edinburgh & District in the 1996 European Cup.

The four previous matches between the two teams in all competitions have all been won by the home side on the day.

Teams:

Glasgow Warriors : 15 Stuart Hogg, 14 Federico Aramburu, 13 Rob Dewey, 12 Troy Nathan, 11 Colin Shaw, 10 Duncan Weir, 9 Henry Pyrgos, 8 Ryan Wilson, 7 Chris Fusaro, 6 Rob Harley (captain), 5 Nick Campbell, 4 Tom Ryder, 3 Ed Kalman, 2 Pat MacArthur, 1 Ryan Grant.
Replacements: 16 Finlay Gillies, 17 Gordon Reid, 18 Michael Cusack, 19 James Eddie, 20 Johnnie Beattie, 21 Colin Gregor, 22 Peter Horne, 23 Tommy Seymour.

Treviso: 15 Willem De Waal, 14 Ludovico Nitoglia, 13 Ezio Galon, 12 Luca Morisi, 11 Brendan Williams, 10 Kristopher Burton, 9 Alberto Chillon, 8 Marco Filippucci, 7 Francesco Minto, 6 Manoa Vosawai, 5 Benjamin Vermaak, 4 Antonio Pavanello (captain), 3 Pedro Di Santo, 2 Diego Vidal, 1 Michele Rizzo.
Replacements: 16 Enrico Ceccato, 17 Matteo Muccignat, 18 Augusto Allori, 19 Valerio Bernabò, 20 Gonzalo Padrò, 21 Simon Picone, 22 Tommaso Iannone, 23 Alberto Di Bernardo.

Referee: Alan Falzone
Assistant Referees: AndyMacpherson, Iain Bruce

Saturday, September 24

Aironi v Edinburgh
(Stadio Zaffanella - 15.00)

Aironi have lost their last seven matches since their 25-13 victory over Connacht at Stadio Zaffanella on 26 March.

Edinburgh gained a first victory of the season at home to Connacht on Friday. The Scotsmen lost on their most recent visit to Italy: 6-31 at Benetton Treviso on 6 May.

Edinburgh took both previous encounters with Aironi last season.

Teams:

Aironi: tbc

Edinburgh: tbc

Referee: Peter Allan
Assistant Referees: Matteo Liperini, Claudio Blessano

Scarlets v Leinster
(Parc y Scarlets - 18.30)

Scarlets have slipped to successive defeats in the Pro 12, but both encounters were played away from home.

The Welshmen have won four of their last five matches at Parc y Scarlets. Scarlets are winless in their last nine clashes
against Irish provinces.

Leinster's only win in their last four matches was 31-10 at home to Newport Gwent Dragons on 9 September. Leinster
slipped up at Ospreys in their most recent away game but have not lost two in a row on the road since September 2010.

Scarlets' only win over Leinster since October 2007 was 18-16 at Parc y Scarlets on 5 September 2009.

Teams:

Scarlets: tbc

Leinster: tbc

Referee: John Lacey
Assistant Referees: Neil Hennessy, HughWatkins
TMO: Tony Rowlands

Sunday, September 25

Ospreys v Ulster
(Liberty Stadium - 16.30)

Something has to give at Liberty Stadium as both Ospreys and Ulster have made 100 percent winning starts to the new season.

Ospreys only reversal in their last 14 home games in all competitions was 20-22 to Munster on 23 April.

Ulster's only regular season defeat since February was 26-34 at Leinster on 16 April. The Ulstermen's only defeat in their
last nine matches against Welsh opponents was in this equivalent game at Liberty Stadium last season.

Each team won its respective home game with the two sides met last season, whilst Ulster's record in previous visits to
Liberty Stadium is won 2, lost 5.

Teams:

Ospreys: tbc

Ulster: tbc

Referee: Dudley Phillips
Assistant Referees: Sean Brickell,Martyn Lewis
TMO: Huw Lewis