Holders Waringstown impressively secured a third Irish Cup final appearance in six seasons as Greg Thompson put Instonians to the sword.

Fresh from his whirlwind century in the previous evening's Twenty20 Cup final victory over his former club Lisburn, Thompson produced another match-winning innings for the Villagers.

This one may have been less spectacular than Friday's sensational 111 off only 55 balls, but his unbeaten 74 was just what Waringstown needed to complete a wonderful weekend double.

Visitors Instonians did well to reach 220 after a faltering first half of their innings, but it felt like an inadequate target given the in-form men in the Waringstown line-up.

Again Adam Dennison didn't translate his fantastic scoring feats for the Northern Knights into Waringstown runs though this time it was injury which held back the teenage opener.

Having recorded ducks on club duty either side of piling up 279 in two interpro innings, Dennison damaged his ankle trying to take a catch in Saturday's semi and had to retire hurt after facing only three balls.

Fellow opener James Hall made 45 but James McCollum and professional Cobus Pienaar fell fairly cheaply to leave Waringstown effectively 75 for four.

That was to be Instonians' last success with the ball, however, as skipper Lee Nelson, another player in decent touch, joined Thompson in a huge unbroken stand of 149.

Thompson was bowled with the scores level at The Lawn the evening before, but fittingly Waringstown's master-blaster sealed this win on the same ground with a six.

That completed what was, by his standards, a relatively pedestrian 74 off 85 balls while the captain's contribution by Nelson was 70 as the hosts reached their target with more than five overs to spare.

Earlier former Irish international Andrew White, who top-scored with 70, and pro Rusty Theron had led the Instonians fightback from the perilous position of 92 for five to post a competitive total.

Gary Kidd took three wickets while the 28-year-old Thompson, whose name is now being bandied about for a call-up to Ireland's ailing Twenty20 team, was responsible for two run-outs.

The final at Clontarf on Saturday week will be a repeat of last year's decider as regular runners-up Merrion overhauled Dublin YMCA with two balls to spare in the other semi-final showdown.

Former Ireland captain Alan Lewis rolled back the years with 48 but another ex-international, Dave Langford-Smith, took four wickets for only eight runs and the prolific John Anderson's 74 not out saw Merrion home.

Both Ulster sides were beaten in the second tier National Cup semi-finals, Woodvale losing at home to Rush and Newbuildings being edged out in a thriller at Laois.

Irish Senior Cup semi-finals: At The Lawn: Waringstown beat Instonians by 7 wickets. Instonians 220-8 (A White 70, R Theron 48, R McKinley 24, Nat Smith 22 not out; G Kidd 3-33) Waringstown 224-3 (G Thompson 74 not out, L Nelson 70 not out, J Hall 45) At Anglesea Road: Merrion beat Dublin YMCA by 4 wickets. Dublin YMCA 251 (S Terry 51, A Lewis 48; D Langford-Smith 4-8) Merrion 257-6 (J Anderson 74 not out, P Tice 63, D Joyce 62).