Sri Lanka 234 for 5 (Asalanka 77, Madushka 69, Motie 3-47) beat West Indies 185 for 4 (Rutherford 74*, Carty 37, Chase 33*, Hasaranga 2-18) by five wickets (DLS method)
A 137-run stand between Charith Asalanka and debutant Nishan Madushka provided the base as Sri Lanka comfortably chased down a DLS-adjusted target of 232 in Pallekele, to take a 1-0 lead in the series.
Asalanka top-scored with a 71-ball 77, while Madushka finished with 69 off 54. Both departed unable to see the chase through, but considering the precarious position at which they had come together - 45 for 3 in the seventh over - they had done more than enough to ensure the win.
Kamindu Mendis was there at the end to see the win through, with an unbeaten 30 off 21, and alongside him was Janith Liyanage on a run-a-ball 18.
Left-arm spinner Gudakesh Motie was the pick of the bowlers for the visitors, with figures of 3 for 47, while Alzarri Joseph grabbed two. Despite having reinforced their spin reserves in preparation for a dry Pallekele surface, none were able to offer as much penetration as Motie.
While Motie too went at over six an over he at least posed a wicket-taking threat. This was not something the pair of Roston Chase and Hayden Walsh Jr. could boast, as they gave up 80 runs in the 10 overs between them.
While this was down to a combination of errant bowling and ruthless batting, the West Indian spinners were also impacted by a wet ball as a result of a wet outfield. The rain also meant that the pitch had become easier to bat on by the time Sri Lanka took lease of the wicket.
Earlier, Sherfane Rutherford's counterattack had been cut short by rain to bring to a premature close the West Indies innings on 185 for 4 after 38.3 overs.
But even with that caveat, the way Sri Lanka approached their chase made them well worth their victory. Madushka, making his debut in place of the injured Pathum Nissanka, opened the innings alongside Avishka Fernando but by the time he faced his fifth delivery in ODI cricket, Sri Lanka had found themselves already two down.
Avishka drove a widish delivery straight to point, while Kusal Mendis - who had looked in good nick with a trio of enterprising boundaries - top-edged an attempted pull. This brought Sadeera Samarawickrama to the crease, and he wasted little time taking the initiative, striking Jayden Seales for three boundaries in the fifth over of the chase.
With the threat of rain looming, Sri Lanka's game plan was clear - get ahead of the DLS equation. But when Sadeera fell, courtesy an absolute peach from Motie that knocked back off stump, Sri Lanka were suddenly at the risk of letting the game slip into dangerous territory - even with the safety of being able to bat until No 9.
But if those watching on were feeling nervous, Sri Lanka's skipper hardly let it show. Off just the second delivery he faced he swept Motie for four, before driving him exquisitely through the covers an over later. Madushka, who up until this point was content to turn over the strike to his more aggressive partners, finally notched his first boundary in the 10th over.
And this partnership scarcely took the foot off the gas as the West Indies struggled to maintain tight lines and lengths. Between the 10th and 20th over only two overs didn't contain a boundary, as Sri Lanka racked up 72 runs in that period. And the scoring only accelerated from that point on, with a further 41 runs scored between overs 20-25.
Madushka eventually edged to slip, with Asalanka following shortly after trapped leg before - both off Motie - but the required run rate had dropped to nearly four an over by that point, and any peril long since neutralised.
West Indies' best period of the game had occurred much earlier. Prior to the rain intervention, they had been in the process of regaining some lost momentum with Rutherford and Chase in the middle of an 85-run fifth-wicket stand off 78 deliveries.
Wanindu Hasaranga had taken two wickets, while Jeffrey Vandersay and Asalanka had one apiece. But on a dry Pallekele surface, West Indies knew a trial by spin was always on the cards after they had won the toss and elected to bat.
Dunith Wellalage was into the attack as early as the fifth over - and even before that medium pacer Liyanage had resorted to offcutters on a hard length - while spin was in effect from both ends not long after.
Despite a promising opening stand it wasn't long before West Indies had stumbled to 54 for 3, with Rutherford joining Keacy Carty in the middle, and the scoring rate now hovering at around four an over. It was during this period that Sri Lanka's spinners took total control, as West Indies were content to play it safe, racking up numerous dot deliveries, and picking up the odd ones and twos.
A Rutherford cut for four in the 17th over was the first West Indies boundary in 47 deliveries; by the traditional halfway point of 25 overs, they had inched to 94 for 3. It was here that a frustrated Carty unleashed a powerful one-handed loft over long-on for six to break the shackles somewhat, but that relief was shortlived as he fell going for a repeat performance the very next delivery. That brought to an end a 46-run partnership - the West Indies' best of the innings until that point.
But with the dependable Chase alongside him, Rutherford continued as before, picking off singles and attempting to pounce on any rare loose deliveries. But as their confidence grew and a persistent drizzle greased the surface, the pair struck 43 in the last five overs they faced. With the death overs still to come, a total in the region of 275 was on the cards. But then the rains came.
