The win, which was achieved with 10.5 overs to spare, gives Dimuth Karunaratne's men an unassailable 2-0 lead in the three-match series.

Sri Lanka's batsmen had managed only six hundreds between them in the 38 one day internationals they had played since the start of 2018, but boosted that total in impressive style.

Opener Avishka Fernando and number four Kusal Mendis dragged the home side out of deep trouble after they had slumped to 2-9 following the dismissals of skipper Karunaratne and Kusal Perera with the innings just 15 balls old.

They had put on 239 for the third wicket when Mendis was caught behind for a run-a-ball 119 before Fernando finally succumbed for 127 with Alzarri Joseph doing the damage on both occasions, but not before Sri Lanka had reached 4-271 with seven overs and four balls remaining.

Thisara Perera's quick-fire 36 helped to push the score to 345 for eight, their highest ODI score against the West Indies, with Sheldon Cottrell claiming 4-67 alongside Joseph's haul of 3-57.

The tourists, who had won the toss and opted to field, got off to a promising start as they attempted to chase down their target.

However, the departures of Sunil Ambris for 17 with 64 on the board and fellow opener Shai Hope for 51 with only 19 more having been added to the total prompted something of a collapse.

Darren Bravo, Roston Chase and Nicholas Pooran, who scored 31, all got starts, but by the time skipper Kieron Pollard had gone without troubling the scorers, they had slumped to 5-131.

Fate intervened briefly when a floodlight failure halted play, but the respite was temporary as, despite resistance from Keemo Paul and Fabian Allen, the West Indies were bowled out for 184 with Wanindu Hasaranga and Lakshan Sandakan claiming 3-30 and three for 57 respectively.

Australian Associated Press