The Windies' 36-run win looked a highly unlikely outcome for much of the game, but in the end, Samuels' belligerent 78 from 56 balls proved decisive.
Samuels saw a clutch of his fellow top-order ball-strikers fail to register on a slow but fair pitch. He did not panic, however, and pushed his team up to 137 for six - a total which, contrary to expectation, proved far too many for Sri Lanka, who were dismissed for 101 in reply.
It was a turn of events which deflated the vast majority in a partisan 35,000 sell-out crowd.
But it may conversely breathe new life into West Indies cricket for years to come, after a generation of mediocrity since the heydays of the 1970s and 80s.
"We haven't won a major title for years now, so I think this is a great achievement for this wonderful team we have here," said Samuels.
"The entire Caribbean embrace this. It means the world to us.
"We're here to show the world that West Indies cricket is back.
"The sky is the limit now."
Samuels, who returned to international cricket last year after a two-year ban for passing information to a bookmaker, added: "My career has had its ups and downs - a lot of tough times.
"But I'm not someone that will ever give up.
"The person that I am deep down inside is the reason I'm still here playing cricket.
"I have a family that believes in me. So if outsiders don't, that doesn't really matter to me.
"Being under pressure on a cricket field is nothing compared to what I've been through off the field."
Captain Darren Sammy was revelling in the success - one he said was for the people of the Caribbean.
"We can definitely cherish this moment - I will for sure - and we can relive it every day of our lives," said Sammy.
"This is the best moment for me in any cricket.
"This is for the Caribbean people, the West Indies fans all over the world.
"They've been craving success. It's party time now from Jamaica down to Guyana - and we know how to party - so they'll need a lot of bartenders."
Even Sammy must have had his doubts when the Windies crawled to 14 for two in the six-over powerplay, after choosing to bat first.
But he said: "God works in mysterious ways - he performs wonders.
"It is the belief we have in the side. We expected them to give us a fight, and they did, but throughout the last year we've been showing that never-say-die attitude.
"We've not been winning games with it. It's been taking us close, but in this tournament we've won games - and that's every man believing that whoever is out there can do the job.
"Today it was Marlon Samuels, and in the end every run counted - and then the bowling and fielding display was just brilliant.
"I said we needed our A-plus game, and we definitely did.
"The momentum we finished our batting with took us through to the bowling.
"Then Ravi (Rampaul) started off really well with his first ball, and we never looked back from there.
"We saved our best for last. This is the icing on the cake."
This was a poignant moment for both Sammy and Samuels, the former a captain whose place in the side has so often been questioned and the latter capping a wonderful year in a previously chequered career.
Neither was ever going to be weighed down by their critics, though.
"I play for the people. The commentators get paid to speak; I get paid to play cricket," added Sammy.
"Anyone can have an opinion about me ... my shoulders are broad enough, and I wear this crest on my heart.
"I don't play for glory; I play for the Caribbean people."
