There were half centuries for Laura (Delany) and Rachel Delaney as the LCU Women's section got under way on Thursday night.
The Irish skipper steered her side to a six-wicket win in their clash with Merrion at Angelsea Road, as they chased down 132 to win in the last over.
Earlier her namesake and fellow international Rachel, had top scored with an unbeaten 54, sharing in a second wicket partnership of 120 with Rebecca Stokell (48).
The pair came together after the fall of Leah Paul for just a single in the first over, trapped lbw by Sophie MacMahon.
It was a rare success for the bowlers on a night where the batters dominated.
"It was great to get our first win of the season in what turned out to be a very competitive game," Laura Delany told CricketEurope afterwards.
"We have a young side this season and whilst we have a few things to work on there is a lot of potential within this group.
"Iím excited to see how the girls progress over the course of the Summer."
Elsewhere Malahide strolled to an emphatic ten-wicket win over Clontarf. Anna Kerrison took 4 for 16 as Clontarf were restricted to 80 for 9.
That the Castle Avenue side made that was due primarily to the efforts of number nine Anna Kirk, who hit five boundaries in an unbeaten 30.
Malahide wasted no time in chasing down the target, with skipper Caoimhe McCann and Amy Hunter taking just 44 balls.
Belfast teenager Hunter hit five boundaries in her 41 not out, while McCann found the ropes three times in her undefeated 35.
Pembroke were convincing eight wicket winners in their clash with YMCA at Claremont Road.
Captain Orla Prendergast led by example as she took 2 for 11 to help restrict the hosts to 102 for 7.
Fellow international Louise McCarthy - back in the Irish set-up this year - also claimed a brace, with Sarah Forbes' 27 the top score.
Prendergast (28) and Louise Little (34) both hit three boundaries as they shared an opening stand of 66 to put the Sydney Parade side well on the way.
Shauna Kavanagh then thumped four boundaries in her 17-ball unbeaten 20, as Pembroke clinched the eight-wicket win with three overs in hand.
LEINSTER WOMEN RESULTS
At Anglesea Road, Merrion 132/2 (20 overs; Rachel Delaney 54*, Rebecca Stokell 48) lost to Leinster 133/4 (19.1 overs; Laura Delany 61*) by 6 wickets
At The Village, Clontarf 80/9 (20 overs; Anna Kirk 30*; Anna Kerrison 4-16) lost to Malahide 81/0 (7.2 overs; Amy Hunter 41*, Caoimhe McCann 35*) by 10 wickets.
At Claremont Road, YMCA 102/7 (Sarah Forbes 27, Orla Prendergast 2-11, Louise McCarthy 2-16) lost to Pembroke 105/2 (17 overs; Louise Little 34, Orla Prendergast 28, Shauna Kavanagh 20*) by 8 wickets.