Tomorrow is an important meeting between India and Bangladesh with both teams needing to win to keep their qualification hopes on track.
Scroll down for highlights from today's game. We'll see you tomorrow.
Post update
Pooran stayed in and reached a maiden international hundred but it was always a tall order when he was batting with the tail.
Sri Lanka then effectively sealed the win when Pooran was dismissed by Angelo Mathews at the start of the 48th over with 31 runs needed.
Post update
West Indies were then the favourites. They needed 57 from 36 balls. If Pooran and Allen had stayed in then they'd probably have won.
But Allen fell to a horrible run out. It was his fault.
Post update
Fabian Allen then breathed life back into the game. He played a stunning hand with 51 from 32 balls from number eight while Pooran kept going at the other end.
Post update
Nicholas Pooran dug in but the Windies hopes faded further when Jason Holder and Carlos Brathwaite were both out.
Post update
A quick recap of that remarkable second innings...
Chasing a record score in a World Cup, West Indies looked out of the game.
They were 84-4 with Chris Gayle and the rest of the top order back in the hutch...
Post update
It was 561 days since Angelo Mathews last bowled in an ODI...
Post update
Sri Lanka captain Dimuth Karunaratne: "To win any match is a great feeling. It gives us lots of confidence. All of the players are doing really well. That is what I was expecting as a captain.
"Pooran and Allen batted really well. The two run outs changed the game.
"Angelo put his hands up and said 'OK I will bowl two overs'. He has that confidence. He did the job. I don't think he is going to bowl much more but if it is a crucial time he might bowl a couple of overs."
Post update
Rihanna has just walked out of the West Indies dressing room with a signed bat over her shoulder.
'Run outs were crucial'
West Indies skipper Jason Holder: "We started slowly out of the blocks, we gave up a lot of runs in the field and that really hurts you. We were sloppy. We have to be better. This entire tournament we havelet key moments slip.
"I felt 338 was about par, it was free-scoring. It was a matter of us getting in and playing some shots. Pooran had an outstanding knock. He gave himself a chance and went deep.
"We finished off their innings reasonably well but we gave them 30-40 runs in the field. That really let us down. We have got in good positions and thrown it away throughout the tournament.
"The run outs were crucial. We were one or two partnerships away."
Get Involved
#bbccricket
Kumaran Ravendradas: A lot of criticism of Windies but we must remember that they have been so bad that they were forced to qualify. They've sometimes not turned up for games but other games we have seen glimpses of class. Their win over Pakistan was awesome. This team has potential.
Sho: That horrible run out between Pooran and Allen was the turning point. They would've chased this with an over to spare had Allen stayed in. Run out was Allen's fault though.
Post update
Graeme Swann
Ex-England spinner on BBC Test Match Special
It is plain to see Chris Gayle should not play anymore for West Indies. He has had a great career. He should bow out gracefully.
Post update
Sir Curtly Ambrose
Former West Indies bowler on BBC Test Match Special
Should Chris Gayle be given a farewell Test, something which has been rumoured?
Nonsense.
He hasn't played a Test for five years. He can barely make it through an ODI. Farewell? What kind of message would that send to an opening batsman.
The time has come for Chris Gayle to say thank you very much, and leave this team gracefully.
Man of the match
Avishka Fernando: "When I went in I was very happy that I did what was required. We batted and bowled well and I'm very happy to get a hundred in a win.
"I am very hapy to get this opportunity. All I focus on is taking this forward and developing my game."
Post update
Graeme Swann
Ex-England spinner on BBC Test Match Special
This game bodes well Sri Lanka's future. There were a couple of shining lights who can have a decade of great cricket ahead of them.
Post update
Sri Lanka's centurion Avishka Fernando wins the man of the match award.
It was his first international hundred.
Post update
Sir Curtly Ambrose
Former West Indies bowler on BBC Test Match Special
It is another replay of the New Zealand game, isn't it? What could have been.
West Indies have the knack of getting into good positions and not finishing the job and that's not going to work.
Post update
Rihanna is now in the West Indies dressing room, hugging the players.
Post update
This is how the table now looks.
Sri Lanka move to eight points but they cannot reach the semi-finals.
That's because the first way teams with the same points are separated is wins - no net run-rate.
BBCCopyright: BBC
Post update
This was the crucial moment.
West Indies needed 31 from the last three overs but Nicholas Pooran was out for 118.
Live Reporting
Matthew Henry
All times stated are UK
Get involved
BBCCopyright: BBC
Latest PostPost update
We've had another thriller. This World Cup keeps on delivering.
Head over here for a full report on an entertaining game.
Tomorrow is an important meeting between India and Bangladesh with both teams needing to win to keep their qualification hopes on track.
Scroll down for highlights from today's game. We'll see you tomorrow.
Post update
Pooran stayed in and reached a maiden international hundred but it was always a tall order when he was batting with the tail.
Sri Lanka then effectively sealed the win when Pooran was dismissed by Angelo Mathews at the start of the 48th over with 31 runs needed.
Post update
West Indies were then the favourites. They needed 57 from 36 balls. If Pooran and Allen had stayed in then they'd probably have won.
But Allen fell to a horrible run out. It was his fault.
Post update
Fabian Allen then breathed life back into the game. He played a stunning hand with 51 from 32 balls from number eight while Pooran kept going at the other end.
Post update
Nicholas Pooran dug in but the Windies hopes faded further when Jason Holder and Carlos Brathwaite were both out.
Post update
A quick recap of that remarkable second innings...
Chasing a record score in a World Cup, West Indies looked out of the game.
They were 84-4 with Chris Gayle and the rest of the top order back in the hutch...
Post update
It was 561 days since Angelo Mathews last bowled in an ODI...
Post update
Sri Lanka captain Dimuth Karunaratne: "To win any match is a great feeling. It gives us lots of confidence. All of the players are doing really well. That is what I was expecting as a captain.
"Pooran and Allen batted really well. The two run outs changed the game.
"Angelo put his hands up and said 'OK I will bowl two overs'. He has that confidence. He did the job. I don't think he is going to bowl much more but if it is a crucial time he might bowl a couple of overs."
Post update
Rihanna has just walked out of the West Indies dressing room with a signed bat over her shoulder.
'Run outs were crucial'
West Indies skipper Jason Holder: "We started slowly out of the blocks, we gave up a lot of runs in the field and that really hurts you. We were sloppy. We have to be better. This entire tournament we havelet key moments slip.
"I felt 338 was about par, it was free-scoring. It was a matter of us getting in and playing some shots. Pooran had an outstanding knock. He gave himself a chance and went deep.
"We finished off their innings reasonably well but we gave them 30-40 runs in the field. That really let us down. We have got in good positions and thrown it away throughout the tournament.
"The run outs were crucial. We were one or two partnerships away."
Get Involved
#bbccricket
Kumaran Ravendradas: A lot of criticism of Windies but we must remember that they have been so bad that they were forced to qualify. They've sometimes not turned up for games but other games we have seen glimpses of class. Their win over Pakistan was awesome. This team has potential.
Sho: That horrible run out between Pooran and Allen was the turning point. They would've chased this with an over to spare had Allen stayed in. Run out was Allen's fault though.
Post update
Graeme Swann
Ex-England spinner on BBC Test Match Special
It is plain to see Chris Gayle should not play anymore for West Indies. He has had a great career. He should bow out gracefully.
Post update
Sir Curtly Ambrose
Former West Indies bowler on BBC Test Match Special
Should Chris Gayle be given a farewell Test, something which has been rumoured?
Nonsense.
He hasn't played a Test for five years. He can barely make it through an ODI. Farewell? What kind of message would that send to an opening batsman.
The time has come for Chris Gayle to say thank you very much, and leave this team gracefully.
Man of the match
Avishka Fernando: "When I went in I was very happy that I did what was required. We batted and bowled well and I'm very happy to get a hundred in a win.
"I am very hapy to get this opportunity. All I focus on is taking this forward and developing my game."
Post update
Graeme Swann
Ex-England spinner on BBC Test Match Special
This game bodes well Sri Lanka's future. There were a couple of shining lights who can have a decade of great cricket ahead of them.
Post update
Sri Lanka's centurion Avishka Fernando wins the man of the match award.
It was his first international hundred.
Post update
Sir Curtly Ambrose
Former West Indies bowler on BBC Test Match Special
It is another replay of the New Zealand game, isn't it? What could have been.
West Indies have the knack of getting into good positions and not finishing the job and that's not going to work.
Post update
Rihanna is now in the West Indies dressing room, hugging the players.
Post update
This is how the table now looks.
Sri Lanka move to eight points but they cannot reach the semi-finals.
That's because the first way teams with the same points are separated is wins - no net run-rate.
Post update
This was the crucial moment.
West Indies needed 31 from the last three overs but Nicholas Pooran was out for 118.