The Northern Knights skittled holders Leinster Lightning for just 114 - the second lowest total in the trophy's seven years - as they completed an emphatic seven wicket win at Sydney Parade.
Batting first after winning the toss, Lightning were rocked by three early blows, with Mark Adair (2-19) striking twice and Graeme McCarter once as they stumbled to 4 for 3 - Jack Tector, Gareth Delany and Lorcan Tucker the victims.
Andy Balbirnie and Simi Singh set about rebuilding the innings, adding 71 for the fourth wicket before the hosts suffered another collapse, as Shane Getkate (3-19) delivered a triple whammy.
The Instonians all-rounder trapped Singh lbw as he top scored with 44, induced a leg-side strangle from Kevin O'Brien (0), and then had skipper George Dockrell - so often Lightning's saviour in previous perilious situations - caught by James Cameron-Dow for 1.
Tyrone Kane (10) and Balbirnie attempted yet another salvage operation, but with limited success as they added 24 for the 7th wicket before another cluster of wickets saw the innings end on 114 all out.
Jacob Mulder (3-5) bowled both Kane and Balbirnie (41), and finished the innings by dismissing Barry McCarthy - Cameron-Dow trapping Josh Little inbetween.
The Knights attacking intentions were signaled by the promotion of Adair to the opening slot in a tricky pre-lunch period.
He clubbed five boundaries in a 17-ball 27, but two wickets for Peter Chase (2-36) and one for Barry McCarthy offered Lightning brief hope at 44 for 3.
However those hopes were quickly extinguished by Knights skipper Gary Wilson and Harry Tector, who both made unbeaten 35's as they shared an unbroken fourth wicket stand of 71 to seal the win with more than 28 overs to spare.
The victory takes the Knights one point behind Leinster with both sides having two matches left. They meet again at Stormont on August 20th in a game that will go a long way to deciding the destiny of the trophy.
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