Round 5 opens with four games on Friday night, including the interprovincial derby at the Sportsground where Connacht host reigning Heineken Cup champions Leinster.
Even though the visitors have an impressive record against fellow Irish provinces, Connacht can take heart from the fact that they were the victors in this equivalent fixture in 2010.
There are also two games in Wales on Friday, the Cardiff Blues taking on Ulster and Newport Gwent Dragons facing Edinburgh.
The Blues have attracted large crowds since their return to the Arms Park, their fans must be hoping the Cardiff side maintains the form that has not seen an Ulster victory at the ground since 2005.
In nearby Newport, visitors Edinburgh have to go back nearly as far to trace their last victory over the Dragons at Rodney Parade, to May 2006, so the odds are in favour of Welsh successes on Friday night.
The remaining fixture in the round sees newcomers Zebre making their second trip to Scotland, this time to face Glasgow Warriors at Scotstoun Stadium. The Italians will be looking for a better return this time having gone down 41-10 at Edinburgh in round 3.
RABODIRECT PRO12 - ROUND 5 FIXTURES:
Friday, September 28 -
Newport Gwent Dragons (10th) v Edinburgh (6th), Rodney Parade, 7pm
Cardiff Blues (3rd) v ULSTER (5th), Cardiff Arms Park, 7.05pm (live BBC 2 Northern Ireland/BBC 2 Wales)
Glasgow Warriors (7th) v Zebre (12th), Scotstoun Stadium, 7.35pm (live BBC ALBA)
CONNACHT (9th) v LEINSTER (4th), the Sportsground, 8pm (live TG4)
Saturday, September 29 -
Ospreys (8th) v MUNSTER (2nd), Liberty Stadium, 6.30pm (live RTÉ Two/S4C)
Benetton Treviso (11th) v Scarlets (1st), Stadio di Monigo, 7.05pm (live SportItalia)