Oshane Thomas destroyed the Sri Lankan batting lineup in a stunning spell of bowling as he took five wickets for 28 runs in the first T20I on Wednesday.
West Indies marched to victory by a margin of 25 runs after racking up an imposing total of 196-4 in 20 overs.
Lendl Simmons smashed an unbeaten 67 while opening the batting, forging healthy stands with all the batters.
In pursuit of the formidable target, Thomas' bouncer-laden fast bowling heavily dented the home side, who were eventually all out for 171 in the final over.
Thomas single-handedly supervised Sri Lanka's top-order collapse, claiming the first five wickets to fall before Kusal Perera and Wanindu Hasaranga desperately tried to seek stability in their 86-run partnership.
Despite being blown away in the preceding one-day series, a rejuvenated West Indies smashed nine sixes in their innings as they dominated the opposition.
Simmons and Brandon King laid the platform for subsequent batsmen to capitalize on the strong start.
Andre Russell, returning to the side since the World Cup, hammered 35 off 14 deliveries while captain Kieron Pollard also fired in a spectacular finish to the West Indies innings. Pollard, playing his record 500th T20 match, hit 34 off 15 balls as he brought up 10,000 runs across his career in the shortest format.
Sri Lanka's top-order batsmen all perished to the sheer tenacity and ferociousness of Thomas' pace bowling. Opener Avishka Fernando, Shehan Jayasuriya, Kusal Mendis and Angelo Mathews were dismissed as a result of flashy shots against the 23-year-old's barrage of short-pitched stuff, leaving them reeling at 56-5.
Pollard hailed Thomas' exceptional performance, stating the fact that it was a "just reward" for the hard work he put in following a vehicular accident last month.
The second of the two-match series will take place in Pallekele on Friday.