A pair of hundreds from Avishka Fernando and Kusal Mendis guided Sri Lanka to 345/8, before their spinners tied the visiting batsmen up to seal a 161-run victory, the largest victory for Sri Lanka over West Indies in the format.
Their innings also beat the previous record for the home side's largest total against West Indies, 338/6 at Chester-le-Street made during the ICC Men's Cricket World Cup 2019, by seven runs, as well as setting a new record for the highest total achieved in men's ODIs without a six, going past the 333/6 England scored against Australia in 2011.
West Indies started brilliantly, having won the toss and choosing to bowl first, as Sheldon Cottrell removed Dimuth Karunaratne and Kusal Perera with consecutive deliveries to reduce the hosts to 9/2.
But Fernando and Mendis put together a sublime 239-run partnership for the third wicket to flip the game on its head, with the pair finally being seperated with under 10 overs remaining in the innings. Mendis was the man to go, having collected his second ODI ton, as he looked to clear the boundary off Alzarri Joseph.
Joseph struck again in his next over, sending Fernando packing for a career-best 127, the 21-year-old's maiden ODI century, with Keemo Paul taking the catch at deep mid-wicket to atone for dropping the opener from the previous delivery. In all the pair of centurions struck a combined 22 boundaries, all of them fours, with the vast majority of their runs coming through excellent running on a large playing area.
Late cameos from Thisara Perera (36 from 25), Dhananjaya de Silva (12 from 5), Wanindu Hasaranga (17 from 10) and Isuru Udana (17* from 9) took the hosts up to a towering total and leaving West Indies needing to make the highest total ever batting second in Sri Lanka.
Shai Hope and Sunil Ambris got the chase off to a steady start until their 64-run partnership was ended by some miscommunication thanks to a wonderful stop close in by Angelo Mathews, who tossed the ball to the bowler's end to find Ambris well short of regaining his ground.
Hope, coming off the back of a hundred in the first ODI, added a 16th fifty to his tally in the format, but fell just a couple of balls later as he mistimed an attempted big hit off the bowling of Mathews. And Darren Bravo lasted only another three overs before becoming Hasaranga's first victim, well caught at slip off the back of the bat having failed to pick the googly.
🚨 RECORD BREAKERS 🚨— ICC (@ICC) February 26, 2020
This partnership between Avishka Fernando and Kusal Mendis is now the highest third wicket stand by a Sri Lankan pair in the history of ODI cricket. pic.twitter.com/gQW8BPQJbj
Roston Chase and Nicholas Pooran combined to stem the flow of wickets, putting on 37 runs together, but Chase's wicket – bowled by Lakshan Sandakan for 20 – prompted another collapse as both Kieron Pollard and Jason Holder were bowled by Hasaranga googlies, the former dismissed for a golden duck, as the Sri Lankan leg-spinner finished his spell with figures of 3/30.
A fabulous grab by Mathews ended Pooran's resistance on 31, and after a brief partnership between Fabian Allen and Keemo Paul, the game rushed to a conclusion. Paul was tricked by a back of the hand slower ball from Nuwan Pradeep, clean bowled for 21 as he was through his shot much too early, and, after a delay due to floodlight failure, the seamer made it two in the over when he cleaned up Alzarri Joseph's off stump from the final ball of the over. Sandakan then had Allen caught at long on first ball of the next over to seal a huge 161-run win for the hosts.
Sri Lanka lead the series 2-0 going in the third and final ODI to be played in Kandy on Sunday 1 March.