However, the home side appeared comfortably on course for victory — bringing up their hundred inside 10 overs with just two wickets down — until the game was decided in the last over.
Needing 15 to win, all-rounder Josh Little (3-29) got rid of the dangerous Dwayne Bravo, one of two wickets to fall in the last over.
With five needed off the last ball and seven wickets down, Hayden Walsh could only wave his bat into thin air in a desperate attempt to win the game.
It was only Ireland’s second victory in T20 cricket over the West Indies who went into the game having swept the ODI series 3-0.
“Everyone is ecstatic, we came so close in that second ODI (lost by one wicket) and it maybe affected us in that third ODI, so to show the bottle and come out against one of the top teams in T20 cricket and get a win was great for the vibe of the team,” said Ireland skipper Andrew Balbirnie.
For the home side, opener Evin Lewis top scored with 53 off 28 balls with six fours and three sixes.
It was Lewis’s sixth T20 half-century and followed knocks of 95 and 102 in the one-dayers.
West Indian captain Kieron Pollard hit a breezy 31 from 15 balls, threatening to take the game away from Ireland.
But the Irish fielders continued to hold their catches to take the game into the last over.
Earlier, Stirling carted six fours and eight sixes in his 47-ball innings for his seventh T20 half-century.
He put on 154 for the first wicket with fellow opener Kevin O’Brien (48).
“It was a really good pitch and I think we put a par score on which showed in the end, we felt we were in the game the whole way through,” said Stirling.
“It was touch and go, but we’re enjoying the tight games — we came out the right side this time, so it’s a nice feeling.” Ireland made 100 off just 6.3 overs and 150 in the 12th over before the West Indies bowlers applied the brakes after the openers fell within two runs of each other.
Bravo, playing an international match for the first time since September 2016, was taken for 18 runs by Stirling in his first over.
But the veteran star recovered to finish with 2-28 off his four overs, clean bowling O’Brien.
Leg-spinner Walsh took 1-25, his sole victim being Stirling caught at deep-midwicket going for the big shot which would have brought him a century.
The second and third games in the series take place on Saturday and Sunday in St Kitts. (AFP)