Munster, however, beat Leinster 19-15 at Thomond Park in Round 5 and are going for a first regular season double over their fiercest rivals since 2008-09.
And Rob Penney's men will be only too aware that any slip-ups could see them finish the weekend in third place with Ulster travelling to Cardiff Blues, also on Saturday.
On Friday night, there's another crucial clash regarding the play-offs with Glasgow Warriors hosting the Ospreys.
The Warriors currently sit in fifth place, four points and one position behind the Ospreys, but they have two games in hand and victory would move them into the box seat.
History is with them - they have won their last five contests with the Ospreys and slipped to four straight away defeats in all competitions.
In one of four matches on Saturday, bottom club Zebre host the Newport Gwent Dragons and both sides will be looking to improve on a run of one win in their last five RaboDirect PRO12 matches.
Cardiff Blues' recent record is worse - they have lost their last five and welcome an Ulster side that have won their last nine in all competitions.
While Sunday's match sees Connacht travel to the Scarlets on the back of four successive victories and victory could well see them into the top half of the table since the opening round of the season.Follow us on Facebook, join the conversation on Twitter, sign up to our YouTube channel for extensive match highlights and sign up for our newsletter for regular updates on the RaboDirect PRO12
63x46.png){kind=logo}