Friday night's third game sees last season's bottom two teams, Connacht and the Newport Gwent Dragons, coming together at the Sportsground in Galway with recent form between the two sides suggesting a home win.
Saturday's two games both kick off at 5.30pm with Munster playing host to the Llanelli Scarlets at Musgrave Park, while Leinster will looking to extend a 20 match undefeated home record in all competitions against Edinburgh in the unfamiliar setting of their new home at the RDS Showgrounds - although the last team to beat them in Dublin was in fact Edinburgh - back in November 2005.
Connacht V Dragons
Referee: Neil Paterson (SRU). Touch Judges: George Clancy (IRFU), Peter Roche (IRFU).
Connachtâ00s only victory in the Magners League since October 2006 was 20-17 at home to Border Reivers on 2 March, whilst the Irishmen have not beaten a Welsh region since this equivalent fixture played on 13 October 2006. However, Connacht have never lost their opening fixture of a new League season.
Newport Gwent Dragons won away from home in the Magners League at Llanelli on 1 September, their first win on the road in the competition since September 2006. The Dragons have not won in Ireland since a 28-21 victory against Ulster at Ravenhill on 8 October 2004.
The last four fixtures between the two sides have all been won by the home side on the day, whilst the Dragonsâ00 last win in Galway was on 1 May 2004.
Ulster V Ospreys
Referee: David Changleng (SRU). Touch Judges: Eanna Oâ00Dowd (IRFU), B Macneice (IRFU)
Ulster have won just one of their last six encounters with Welsh opponents in all competitions: 14-7 at home to the Dragons on 16 February.
Ulster have only lost once before in their opening match of a League season: in 2003 away to the Ospreys.
This is Ospreys worst start to a league campaign with two successive defeats so far, although they have won their last four matches against Irish opposition.
The Ospreys have had the better of their previous League encounters with Ulster winning five games to the Irishmenâ00s three.
Leinster V Edinburgh
Referee: Phil Fear (WRU). Touch Judges: Colin Stanley (IRFU), J Peake (IRFU)
Leinster have won their last 20 home matches in all competitions since Edinburgh won 27-13 at Donnybrook on 6 November 2005. Leinster have won four of their last five matches against Scottish opponents.
Edinburghâ00s only win in their last eight games in the Magners League since January was 30-20 over the Dragons at Murrayfield on 6 April.The two teams met on four occasions last season with all fixtures going the way of the home side on the day.
Munster V Llanelli
At Musgrave Park, 5.30pm.
Referee: Peter Allan (SRU). Touch Judges: D Keane (IRFU), P Haycock (IRFU). TMO: Olan Trevor (IRFU).
Munster have won their last four matches in the Magners League, and have also won five of their last six games in the competition at Musgrave Park.
Llanelli Scarlets have won four of their last five matches in the Magners League. The Scarlets have beaten Irish opponents in seven of their last nine such encounters in all competitions.
The last seven League encounters between Munster and the Scarlets have all gone in favour of the home side on the day.