If it was a bad day for the NW and the NCU, then that wasn't the case for Leinster as no fewer than 8 of their ranks made it through to the draw for the second round, with the possibility of a 9th after no play was possible in the Phoenix v CSN game.
Robert Forrest had the performance of the day, hitting 16 fours and 2 sixes as he carried his bat in making an unbeaten 154 as Clontarf racked up 287-5 against Cork Harlequins at Castle Avenue.
Forrest shared in an opening stand of 165 with Bill Coghlan (58), and from then on there was only going to be one winner.
Cork eventually were dismissed for 153, with Poynter, Ryan and Watterson each picking up two wickets.
YMCA won on the road at Shaw's Bridge against Instonians, as new signing Trent Johnston scored an unbeaten 66 as they chased 147 to win by 6 wickets, despite the best efforts of their Irish passport holding Australian professional Mick Delaney who claimed 3 for 38.
Earlier Ireland A captain James Shannon had top scored with 62 for Instonians, with Sameer Dutt (3-35)the most successful of the YM bowlers.
Merrion won on the road at Ballymena thanks to an unbeaten 67 from their skipper John Anderson. The 2010 winners scored 191-7 which proved 53 too many for Ballymena. Ireland Under 19 hopeful Tyrone Kane took 4 for 15, while the experienced Damian Poder had figures of 3 for 35.
Leinster also enjoyed their trip to the NCU, emerging four wicket winners with just one ball left. Stephen Moreton proved his value to his new club in making a match winning 57 as they successfully chased 157.
Bajan professional Joel Leacock's magnificent start to his Rathmines career continued as he took 4 for 34, with only Nathan Waller (42) making any meaningful contribution to the Lisburn total.
In the final game, Derriaghy long journey to The Mardyke was rewarded by a five wicket win. Cork were skittled for just 96 with Gilliland and Hewitt each claiming two wickets. Andrew Kenny with an undefeated 24 saw them over the line in a five wicket win.
The Phoenix v CSN game will now be played at Stormont on May 27.