Kusal Mendis hit an unbeaten 68 to help clinch Sri Lanka's first T20 international series win over the West Indies with a thumping nine-wicket victory in the third and final game on Thursday.
Sri Lanka chased down their 163-run target with 12 balls to spare as a sell-out home crowd in Dambulla erupted.
"Happy to get the team over the line," said Mendis who hit five fours and three sixes.
"Not the easiest pitch to bat on, but these are conditions that we are used to playing."
The tourists had a chance to dismiss Mendis when he was on 44, but Roston Chase could not hold on to a tough return catch.
Mendis and fellow opener Pathum Nissanka put on 60 runs in just 5.2 overs.
Nissanka, in sublime form, contributed 39 from 22 deliveries, including seven fours and a six, before a low delivery from Gudakesh Motie ended his stay.
Mendis continued his composed knock, driving the spinners effortlessly through the covers and pulling the seamers with authority.
He was joined by Kusal Perera, whose unbeaten 55 off 36 balls showcased his resilience as he battled cramps to reach his 15th T20I half-century.
Together, Mendis and Perera stitched an unbroken 106-run partnership, steering Sri Lanka to a landmark victory over the higher-ranked tourists.
WINDIES IN A SPIN
The West Indies opted to bat and rallied from a shaky start that left them 68-5 with a 54-run stand off 26 balls between skipper Rovman Powell and Motie.
Motie blasting Dunith Wellalage for three consecutive sixes and a four in the 15th over, later departing when Mendis stumped him off Wanindu Hasaranga.
Sri Lanka leaned heavily on their spin arsenal with Maheesh Theekshana and Wanindu Hasaranga claiming two wickets each.
"I thought we had enough runs on the board," Powell said.
"Sri Lankan spinners completely outplayed us. We knew spin was going to play a key role and Sri Lanka were far better."
The West Indies won the series opener by five wickets and Sri Lanka bounced back with a commanding 73-run victory in the second game.
This series win crowns a strong three months for Sri Lanka under new head coach Sanath Jayasuriya.
The team broke a 27-year drought by winning an ODI series against India in July then won a test in England for the first time in a decade.
Earlier this month they swept a two-test series at home against New Zealand – their first series win over the Kiwis in 15 years.
SRI LANKA: Pathum Nissanka, Kusal Mendis (wk). Kusal Perera, Kamindu Mendis, Charith Asalanka (capt), Bhanuka Rajapaksa, Wanindu Hasaranga, Dunith Wellalage, Maheesh Theekshana, Matheesha Pathirana, Nuwan Thushara.
WEST INDIES: Rovman Powell (capt), Roston Chase, Shai Hope (wk), Alzarri Joseph, Brandon King, Evin Lewis, Gudakesh Motie, Sherfane Rutherford, Romario Shepherd, Fabian Allen, Shamar Joseph.