Dublin University beat Terenure by 9 wickets, while The Hills and Railway Union had convincing wins over Malahide and Phoenix.
At College Park, Mikey O'Reilly (3-16) set the tone for the day as he removed both Terenure openers in the first over of the day, as the visitors struggled from the off,
Henry Dall top scored with 30 and Zubair Khan made 24, but a total of 129 was never threatening.
There were three wickets too for Gavin Hoey, and two for Jack Atkinson.
Trinity openers Sanil Gupta and David Vincent blunted the Terenure attack as they shared an opening stand of 99 before Vincent fell for 29.
Skipper Gupta was unbeaten on 70 (5 fours, 1 six), while Nic Pretorius raced to the finishing line with a rapid 23 in just 12 balls to secure a comprehensive nine-wickets win.
At Phoenix Park, there was another opening stand of 99, as Kenny Carroll and Ashil Prakash (42) laid a solid foundation for Railway Union.
Carroll hit 6 fours and 2 sixes in a top score of 69, while Liam McCarthy (39) and Hashir Sultan (23) also made runs as they posted 222.
There was no George Dockrell in the Phoenix ranks, for whom Danish international Oliver Hald (3-52) was the most successful.
A fifth wicket stand of 86 in 13 overs between Tyrone Kane (56) and Adam Chester (34) looked to have the contest in the balance at 141 for 4, before Phoenix collapsed.
Hashir Sultan took four wickets as six wickets fell for 16 - Phoenix 157 all out, losing by 65 runs.
The Hills earned Fingal bragging rights as they brushed aside Malahide in a one-sided contest.
Three wickets apiece for Matthew Weldon (3-18) and Dylan Blignaut (3-25), plus two for Ashley Bain (2-14) saw Malahide bundled out for just 88 - Fintan McAllister the last man out for 24.
Murray Commins hit 8 fours and 2 sixes in an even time unbeaten 53 to seal a comfortable seven wickets win.
At College Park, Dublin University beat Terenure by 9 wickets
Terenure 129 all out (43.4 overs; H Dall 30, Z Khan 24; M O’Reilly 3-16, G Hoey 3-46, J Atkinson 2-7)
Dublin University 131/1 (37.2 overs; S Gupta 70*, D Vincent 29, N Pretorius 23*)
At Phoenix Park, Railway Union beat Phoenix by 65 runs
Railway Union 222 all out (48.4 overs; K Carroll 69, A Prakash 42, L McCarthy 39; O Hald 3-52, D Ranolia 2-53)
Phoenix 157 all out (39.5 overs; T Kane 56, A Chester 34; H Sultan 4-19, S Safi 2-10)