Sri Lanka 345 for 8 (Fernando 127, Mendis 119, Cottrell 4-67, Joseph 3-57) beat West Indies 184 (Hope 51, Hasaranga 3-30, Sandakan 3-57) by 161 runs
Kusal Mendis and Avishka Fernando dovetailed beautifully through the middle overs, producing an effortless 239-run third-wicket partnership that became the bedrock of Sri Lanka's 345 for 8, and by extension, their series-sealing 161-run victory over West Indies. Mendis hit a run-a-ball 119 and Fernando made 127 off 123 deliveries, as they punished West Indies' indiscipline with the ball and sloppiness in the field, rescuing Sri Lanka from a scoreline of 9 for 2 in the third over.
Although the surface clearly suited batting, and a stiff wind across the ground made things difficult for bowlers, a target of 346 was always going to be daunting. And West Indies never really had the measure of this chase. There was a mildly positive 64-run opening stand, as well as a customary Shai Hope fifty, but at no stage did they manage to put Sri Lanka under pressure.
What will especially lift the hosts is that it was their wristspinners that sewed this game up - Wanindu Hasaranga and Lakshan Sandakan taking three wickets apiece through the middle overs to send West Indies into a nosedive. Sandakan claimed the final wicket in the 40th over to finish with figures of 3 for 57. Hasaranga was more impressive, returning 3 for 30 from his 10. Each of his wickets came via the googly, which West Indies' batsmen repeatedly failed to pick.
Coming in at 9 for 2, Mendis had had a nervy first six deliveries - beaten second ball, dropped on two by Kieron Pollard soon after, then rapped hard on the gloves by a Jason Holder delivery that leapt at him from a length. But he settled quickly after the early chance, working his way through the Powerplay with Fernando. Sri Lanka got to 49 for 2 after 10 overs but really it was in the period that followed that the two young batsmen began to flourish, in lock-step, almost never more than 10 runs apart from each other.
With West Indies' quicks frequently straying into the pads, unable to contend the wind that blows across Sooriyawewa, Mendis and Fernando accumulated freely into the ground's vast, unguarded spaces, on the legside in particular. When they hit boundaries, generally they were punishing short balls, which tended to sit up on this surface. Mendis was particularly prolific with the pull shot, while Fernando heaved across the line to good effect as well. They also ran exceptionally well between the wickets, frequently putting pressure on fielders, who would fumble or send in wayward, harried throws.
When the spinners came on, their progress seemed even more effortless. Neither Fabian Allen nor Roston Chase got a lot of turn off the pitch, and these two batsmen were by now experts at hitting gaps. Fernando may just about have played the better innings in the end, but no two single strokes were more alluring than Mendis' advancing, inside-out hits over cover against Allen in the 26th over. He had reached fifty off the 55th delivery he faced; Fernando got to his-half century off his 56th ball.
The pair marched almost inevitably to their hundreds - each advancing steadily and surely through the nineties to get to the milestones in successive overs - Mendis in the 37th off his 107th ball, and Fernando in the 38th off his 109th. Such was the evenness of their progress, that at this stage, they had only hit 15 fours between them, Mendis striking nine of those. With only two wickets down, the score at well over 200, and the death overs now upon them, they started hitting out, Mendis hitting three more fours before eventually top-edging Alzarri Joseph. Fernando hit four more boundaries before holing out to deep midwicket.
Their partnership was not only the best ever at this venue, it was also Sri Lanka's third-highest in all of one-day cricket. It came at better than a run-a-ball as well, which meant it had provided an outstanding platform for the lower middle order. Thisara Perera did the most to do justice to the base Mendis and Fernando had given, hitting 36 off 25 balls. Dhananjaya de Silva, Hasaranga and Isuru Udana also provided cameos, as West Indies' fielding effort became exceedingly frayed through the death overs.
Hope floated through the early overs of the chase, hitting some exquisite legside boundaries to set himself on his way, but then he ran Sunil Ambris out, and before long, was out himself for 51 off 65 balls, chipping Angelo Mathews to short midwicket. Then Sri Lanka's wristspinners took over.
Bravo didn't pick Hasaranga's googly and edged to slip, where de Silva took an excellent catch. Chase then let a beautiful Sandakan stock ball wriggle between bat and pad and clatter into his stumps. Pollard followed soon after, in similar fashion, but to the bowling of Hasaranga. By the time Holder was out, also bowled by a googly, West Indies were 130 for 5 in the 31st over, and never really looked like they would make much of the chase.
Keemo Paul and Allen had a little bit of fun, but even that didn't last long, as Nuwan Pradeep came back to take two wickets in an over. After the first ODI had been decided in a tight finish, this was a proper thumping.
Andrew Fidel Fernando is ESPNcricinfo's Sri Lanka correspondent. @afidelf