A five wicket burst in 11 balls saw Waringstown claim a sensational 13 run (DLS) to claim a place in the T20 Final.
A 49 run partnership between Greg Thompson and James Cameron-Dow was as good as it got for Waringstown who were unable to push on in the final few overs of their innings when a late spell from Josh Manley claimed two wickets while he also effected two run outs.
After Fazal and Burns had added 59 for the first wicket - Greg Thompson had Fazal stumped before 2 in 2 by James Cameron-Dow stalled Lisburn's progress.
Another double strike from Thompson in his next bowling Adam Berry and Matthew Humphreys.
Five wickets had fallen in 11 balls when Phil Eaglestone removed David Millar with his first delivery before further rain ended play.
Instonians top scorer Shane Getkate's 40 ball innings contained 7x4s and 5x6s as they posted a vulnerable looking 116 in an innings that was reduced by rain before the start and again mid innings.
With Ross Adair setting off at his usual blistering start it was odds on for a quick finish but Instonians hauled the rate back and in the end it was a sedate Adair who finished unbeaten and a swift injection of runs from Tyron Koen that saw CIYMS into the Final.