Tammy Beaumont hit 62 as England posted 163/8 before a disciplined bowling display secured a dominant 47-run win for the hosts despite Deandra Dottin's 69.
England got off to a strong start after electing to bat first before Stafanie Taylor claimed Windies' first wicket in the sixth over of the England innings with the score on 43, as Danni Wyatt edged one which went on to glance the stumps with just enough force to dislodge a bail.
Taylor soon had her second wicket as Britney Cooper clung on to a tricky chance to send Nat Sciver on her way. Beaumont continued to mix delicate paddle sweeps with powerful shots down the ground as she kept the innings moving at the other end.
Heather Knight and Amy Jones helped the opener to push the innings along with quickfire twenties to take the hosts to 136/3 before Beaumont fell to Shakera Selman in the 16th over.
That wicket prompted a fightback from West Indies' bowlers as they claimed a wicket in each of the last five overs to restrict England to 163/8, with Selman finishing with 3/26 from her four overs.
England's bowlers kept things tight early on, and the pressure caused Hayley Matthews to attempt a shot over the top off Sciver, only to find the hands of mid-off.
While Deandra Dottin held firm, despite struggling to display her usual clean hitting early on, Sarah Glenn struck with her third ball to remove Taylor immediately after the end of the Powerplay.
Lee-Ann Kirby kept Dottin company for a while, before a mix-up between the pair gave England a simple run out.
Dottin kept fighting, and she deposited Sarah Glenn for a huge six over the leg-side, hitting it out of the ground, shortly before reaching her 11th T20I fifty.
Sciver returned to have Shemaine Campbelle stumped as the visitors slid towards defeat despite Dottin's commendable efforts, and by the time Sophie Ecclestone bowled Dottin the game was all but over, and even more so when two balls later, the England spinner trapped Chinelle Henry in front to end with figures of 2/19 from her four overs.
A disciplined final over from Katherine Brunt meant she finished with miserly figures of 0/8 from her full allocation as West Indies ended 116/6, with England claiming a 47-run victory.
The second T20I will be played at the same venue on Wednesday, 23 September.