Garryowen and Clontarf finished level on points at the top of the AIB League Division 1 guaranteeing them both a home semi final this weekend.
Garryowen beat UCD by 37 - 24 to finish at the top of the table on 61 points and set up an all Limerick semi final at home to Shannon who finished on 56 points in fourth place after beating Ulster Cup Winners Belfast Harelquins by 31 - 15.
Clontarf, second in the league table, beat Galwegians by 32 - 6 to ensure their home tie against Cork Constitution, who beat Dublin University by 33 - 21 and condemned the Trinity men to relegation with a late try.
The semi finals will take place on Saturday with the final to take place in Lansdowne Road a week later.
Irishrugby.ie readers have Shannon slightly ahead on 37% as favourites to win the title, with Clontarf and Garryowen on 23% apiece and Cork Con on 17%.
Castle Avenue and Dooradoyle will be the places to be on Saturday to see which of the four will survive.