West Indies, set a revised target of 230 runs off 41 overs, fell short at 190 for 9 at Port of Spain.
Port of Spain: Kumar Sangakkara struck an unbeaten 90 and captain Angelo Mathews starred with bat and ball Monday as Sri Lanka defeated West Indies by 39 runs in the rain-affected fifth one-day international of the Celkon Mobile Cup.
Sangakkara lashed six fours and a six in 95 balls as the visitors reached 219 for 8 off 41 overs during a rainy morning session at Queen's Park Oval after resuming on 60 for 3 off 19 overs from overnight.
Mathews, in his 100th match, contributed a vital 30 off 26 balls with two fours and two sixes. Fast bowler Kemar Roach, who had undermined Sri Lanka on Sunday before the rain, ended with 4 for 27 while fellow Barbadian Jason Holder grabbed 2 for 50.
West Indies, set a revised target of 230 off 41 overs, fell short at 190 for 9.
Mathews returned to grab 4 for 29. Shaminda Eranga took 3 for 45, and Lasith Malinga claimed 2 for 42 to keep the hosts in check. Darren Bravo top-scored with 70 off 84 balls and shared a restorative fifth partnership of 123 with Lendl Simmons, who scored 67 off 79 deliveries on his return to the team.
West Indies' pursuit had been rattled by Mathews and Eranga, who shared four early wickets as the hosts slumped to 31 for 4 inside the first nine overs.
Mathews took the important wicket of Chris Gayle for 14. The dangerous left-hander skewed to backward point off the outside edge. Eranga struck twice in the next over to further derail West Indies. He pouched a fine, low return catch to remove Johnson Charles for 14 and then induced Marlon Samuels to edge to Mahela Jayawardene at first slip.
When Mathews trapped Devon Smith plumb leg before wicket, West Indies were in ruins. But the two Trinidadians, Bravo and Simmons, in front of an enthusiastic home crowd, gradually brought the hosts back into the contest.
Simmons, after taking 16 balls to get off the mark, eventually started to find his touch and the boundaries with more regularity. He brought up his half-century with his fourth six, off 70 balls, and was soon followed by Bravo, who took 63 deliveries to reach the mark.
The crowd was starting to believe again when Eranga and Malinga doused the hopes with two wickets at the same score.
Simmons holed out to deep cover to provide Eranga with his third scalp, while Malinga grabbed his first when captain Kieron Pollard nibbled outside the off stump and edged to wicketkeeper Kumar Sangakkara. Pollard fell for his third duck of the series.
Malinga also removed the power-hitter Darren Sammy to give Sri Lanka the upper hand again. Sammy skied to the leg side and Malinga held a well-judged running catch.
Bravo, after hitting four fours and a six, holed out in the deep off Mathews.
When Mathews removed Jason Holder first ball, the West Indies were 177-9 and needed seven more runs to stop Sri Lanka from gaining a bonus point which would have assured their place in Thursday's final.
Last pair Kemar Roach and Tino Best ensured that in an unbroken stand of 12. But West Indies' hopes of qualifying now rest with Sri Lanka and India, who meet at the same venue on Wednesday in the final group match.
Sri Lanka lead the table with nine points and a positive run rate while West Indies also has nine points but an inferior run rate. India has five points and must win on Wednesday to have any chance of advancing.
Earlier, Sri Lanka's innings was built around Sangakkara's master class, which started on Sunday's first day.
The left-hander stretched his fourth wicket stand with Lahiru Thirimanne to 64 once play got under way nearly two hours late on the reserve day. Thirimanne scored a valuable 23 off 73 balls. Sangakkara and Mathews added a further 46 for the fifth wicket either side of another rain interval.
Roach returned to claim Mathews and Jeevan Mendis and Sri Lanka were at the crossroads at 147 for 6 with six overs left. But Sangakkara dominated and the visitors added 72 off the final 36 deliveries to give them the momentum going into the break.