The Ospreys secured a home semi-final in the inaugural Magners League Play-Offs on Friday night, while Glasgow Warriors could yet do the same
The Ospreys claimed a 42-10 bonus-point win at home to Newport Gwent Dragons to move to the top of the standings, with their total of 52 league points meaning they will finish no lower than second at the end of the regular season.
Ryan Jones, Dan Biggar, Nikki Walker and Ryan Bevington all crossed for the Ospreys, who were also awarded a penalty try at the Liberty Stadium.
Glasgow also kept their hopes of a home Play-Off alive after they matched the Ospreys in ending their regular season with maximum points.
DTH van der Merwe, Calum Forrester, Hefin O'Hare and Bernardo Stortoni were all on the scoresheet as Sean Lineen's men ran out 37-32 winners at the Scarlets.
The five-point tally takes Glasgow up to 51 points - a point ahead of previous leaders Leinster who play on Sunday.
The Dubliners now know they must claim at least a losing-bonus point against Edinburgh at the RDS to secure a home semi-final ahead of the Warriors.
Anything less would see Leinster finish third, with the Ospreys first and Glasgow second.
For Leinster to regain top spot and secure home country advantage if they were to then make it the Grand Final, they must pick up at least two league points on Sunday.
Any sort of victory, a draw or even a losing bonus point together with a try-scoring bonus would be enough for Leinster to achieve that goal.
There is still one Play-Off spot left to play for, with either Munster, Cardiff Blues or Edinburgh set to join the Ospreys, Glasgow and Leinster in the semi-finals.