Round 17 of the RaboDirect PR12 kicks off with five games on Friday night, with both contenders for the top spot in action.
Leaders Ulster, who have been at the top since round five, welcome Benetton Treviso to Ravenhill while Glasgow Warriors host Cardiff at Scotstoun. _
Having lost out to their nearest rivals, Glasgow Warriors, the last time out, Ulster are now only three points clear at the top and must be hoping for a victory over Treviso to help them hold on to the top spot for the remaining six rounds, and claim one of the coveted home play-off berths.
The only time Glasgow Warriors have topped the table was over the Christmas/New Year period in 2009/10, but they are the form team of the moment, having claimed bonus-point wins in their last four outings, and will be hoping to continue that roll against Cardiff Blues
There is a settled look to the top of the table, the first three places have been the same for the last four rounds but, should Warriors slip up, Leinster are poised to claim advantage, if they are able to overcome Dragons at Rodney Parade.
Scarlets meanwhile, who dropped out of the play-off zone following their defeat in Leinster last weekend, welcome Edinburgh Rugby to Parc y Scarlets, a venue the visitors have won at just once, in 2009.
The round wraps up on Saturday when two of the protagonists for a top four finish, Munster and Ospreys, who face each other at Thomond Park.
History suggests that Munster have the better record of these clashes at Thomond Park, but Ospreys have taken the spoils in the last four meetings between the teams, so this game is finely balanced.