A spectacular century by Glen Adams was the highlight of the Ballymena innings, his 59-ball effort including 6 fours and 7 sixes.
The Ballymena innings was interrupted by rain and one over was lost which increased the Cregagh target to 147.
In the end they came up just short when at one stage they looked comfortable in the chase, the late introduction of Mark Stinson who claimed two quick wickets proving crucial to Ballymena's cause.
Armagh opener Jamie Rogers with the only double figure score in what was a disappointing effort by the batting lineup making just 100.
Wickets were shared around, Shane Henderson with two in a thrifty four-over spell and one each for Gill, Britton, Suresh and Karthik.
Victors Muckamore: Pic by Dave Pettard
There was no trouble for Muckamore chasing down that underpar total with openers Srinivanasan and Suresh adding 69 for the first wicket before Ewan Wilson came to the crease to hit two sixes and a four to see his side home.
The final will take place on Sunday July 23rd.