In Division Two, Dublin University qualified for the final - where they'll play either UL Bohemians or UCC who play tomorrow - when they had a narrow 19-16 win over Old Belvedere at Merrion Road.
In Division Three, Greystones defeated City of Derry 33-28 but there was an upset in the other semi whjen Ards accounted for Highfield 33-19 at Woodleigh Park.
In Temple Hill, Con led 10-3 at half time but saw that lead reduced to just four points early in the second half when David Connellan landed his second penalty. However a scintillating run from the outstanding Anthony Horgan set up the crucial try for Jean-Vincent Igarza and with David Pusey and number 8 Brendan O'Connor excelling up front, Con ran out comfortable winners.
In Thomond Park, first half tries from Brian Tuohy and Mossie Lawlor helped the home side to a 15-3 interval lead. Ajay Derwin then landed a 47th minute penalty and a Rory Best try nine minutes later opened the possibility of a major upset as Shannon found themselves with just a two point cushion (15-13). However Tommy Cregan landed three penalties in the closing quarter while Andrew Thompson struck a cracking drop-goal to send Shannon to Lansdowne Road for the final next Saturday.