Lee Nelson and Greg Thompson produced one of the great Irish Cup partnerships at The Lawn as holders Waringstown beat Instonians to book a repeat of last year's final with Merrion.

The villagers, aiming for a third Irish Cup triumph in the space of just six years, beat their NCU Premier League rivals by seven wickets thanks to an inspired unbeaten stand between the captain and in-form Thompson.

Coming together with Waringstown teetering on 75 for three, with professional Cobus Pienaar and James Hall having departed in the space of two balls, the Northern Knights pair produced a breathtaking partnership of 149 that took Waringstown home with 5.1 overs to spare.

When first Pienaar, edging a flat-footed drive behind off Robert McKinley, and then Hall followed, after making 45 from 61 balls, got a leading edge off Andrew White, you could have argued Instonians were in the driving seat.

Adam Dennison, the opener, had only been able to bat for two balls before retiring hurt with a serious-looking ankle injury, and with David Dawson on holiday, the lower order had an inexperienced look.

But in truth Instonians, despite their fine bowling attack, barely got another look-in on a flat pitch offering nothing to their plethora of seam options.

If anything, Nelson's innings was the more admirable. The Waringstown captain has had tough periods with the bat this summer, but this was a remarkable knock, an exercise in composure but also shot-making. You got the impression that when early in his innings he almost got down on one knee to drive Nathan Smith gloriously through the covers that more than a touch of the old swagger was coming back.

Thompson, fresh from his astonishing Twenty20 Cup final century against Lisburn the previous night, was initially cautious, playing himself in before embarking on a now trademark flurry of boundaries.

Neither could take liberties in view of the pressure-cooker situation but as the victory line came into sight, came the cue for Thompson in particular to unleash. He effectively ended the game as a contest as Stephen Bunting's spin experiment started with three successive boundaries and Waringstown secured that August 27 date with Merrion at Clontarf as Thompson crashed a monster six off Rusty Theron over long-on.

Nelson's unbeaten 70 came from 82 balls and contained seven fours and a six. Thompson, who struck nine fours and a six, was unbeaten on 74 from 85.

Instonians might actually have thought they had enough runs at halfway, 220 for eight representing a significant recovery from 10 for two, 38 for three and 92 for five.

Crucially, James Shannon was one of three wickets for left-arm spinner Gary Kidd (3-33) but White fought valiantly, striking eight boundaries in his 70 from 122 balls and 250 was probably on when he and Theron were adding 54 for the sixth wicket.

But he too fell to Kidd, trying unsuccessfully to clear the in-field in the 38th over, so it was left to Theron (48 from 63), Rob McKinley (24) and Nathan Smith, with 22 from just 12 balls, to take Inst past 200.