The current leaders face third placed Cardiff Blues at the Arms Park on Friday night and with the Blues also still having a chance of winning the league, they will pose tough opposition for a Leinster side who can secure the trophy with a bonus point win.
Should Leinster fail to win, the Ospreys could lift the title on Saturday with a win against a Border Reivers side who will be playing their last ever game. The Ospreys would still be crowned champions if Leinster win without a bonus point and the Welsh side manage to collect five points in Scotland.
However, a bonus point win for the Blues on Friday night coupled with a defeat for the Ospreys could see the Cardiff-based outfit take the title.
Elsewhere, there are three other games which, although they have no have no bearing on the title chase, will still be keenly contested. Llanelli Scarlets, with only one home league defeat since September 2005, face Connacht at Stradey Park. For their part Connacht will be looking to end the campaign on a high after suffering four straight league defeats.
Also on Friday night, Ulster face Edinburgh at Ravenhill, a ground where the Scottish side have not won since 2002. The final game sees form side Glasgow Warriors look to claim another big scalp after last weekend's win over the Ospreys, when they travel to Munster. The Warriors are looking for a fifth straight league success, and have beaten Munster in their last three meetings.
ROUND 22 FIXTURES -
- Friday, May 11 -
Cardiff Blues v LEINSTER, Arms Park, 7.10pm (live BBC Wales/Setanta Sports)
Llanelli Scarlets v CONNACHT, Stradey Park, 7.10pm
ULSTER v Edinburgh, Ravenhill, 7.30pm
- Saturday, May 12 -
Border Reivers v Ospreys, Netherdale, 5.30pm (live S4C)
MUNSTER v Glasgow Warriors, Musgrave Park, 5.30pm
MAGNERS LEAGUE PERMUTATIONS -
A bonus point win for Leinster and they are champions. Any other result and the Ospreys will know exactly what will be required on Saturday for the Welshmen to claim the title at Netherdale.