It will be an all-Ulster final in the Ulster Plate next month after North Down II beat Donemana II in Sunday's semi final at The Holm.
Batting first, the visitors amassed 380 in their 40 overs with Daniel Graham scoring 124 and Alistair Shields 94. James Cameron-Down, two days after helping North Down win the Twenty20 Cup final, took three for 34 as Donemana were restricted to 290.
Their opponents in the final will be Waringstown II who beat Woodvale II by eight wickets at The Lawn with Andrew Mitchell hitting a mammoth 156 not out as the Villagers reached their target of 266 in just 30 overs. Jamie Matthews stayed with him to the finish with an unbeaten 56 as the last 142 runs came in just 10 overs.
The final is on Sunday August 18 at a venue to be confirmed.
It was a second semi-final in 24 hours for North Down II after their victory over Saintfield in the Junior Cup at The Green. Andrew Haire was man of the match with four for 14 and 58 as North Down passed Saintfield's total of 154 with three wickets to spare.
In the final at Belmont on August 3, they will meet Civil Service North II who defeated holders Cooke Collegians II by four wickets. Wayne Horwood, left out of the 1st XI, and Trevor Dalzell both scored 40s as the Stormont side reached the final.