CIYMS reached the final of the Ulster Plate with an exciting five-run win against Donemana in a rain-affected contest at Belmont.
John Matchett top scored with 32 as the home side posted 114 for 7 with Chris Robinson chipping in with 30.
Kyle Dougherty (2-19) was best with the ball for the visitors, and it was he who took the attack to CIYMS.
He hit a valiant 40, but CIYMS held their nerve to seal the win - Peter McCreery (2-10) and Ben Smith (2-23) taking two wickets apiece.
CIYMS will now face the winners of the other semi-final between Brigade and CSNI who are scheduled to meet at Beechgrove on Sunday.
ULSTER PLATE SEMI-FINAL
At Belmont, CIYMS beat Donemana by 5 runs
CIYMS II 114-7 (J Matchett 32, C.Robinson 30, K Dougherty 2-19)
Donemana II 109-8 (K Dougherty 40, P McCreery 2-10, B Smith 2-23)