India captain MS Dhoni smashed 16 off the first four balls of the final over to clinch the Tri Nation series with a thrilling one wicket victory over Sri Lanka in Port of Spain on Thursday.
After bowling out Sri Lanka for 201, India were facing defeat at 167 for eight but, needing 15 to win off the final over, Dhoni smashed Shaminda Eranga for a six and a four and then won the game with another six with two balls to spare.
The victory continues India's success in the one-day game following their triumph in last month's Champions Trophy.
Hosts West Indies finished third in the series having failed to make the final, which resulted in a disappointing crowd.
Eranga will surely regret his decision to bowl full length deliveries around off stump to Dhoni, allowing the Indian the room to drive.
But for Dhoni, returning from a hamstring injury and looking uncomfortable running between the wickets, it was a superb effort, his unbeaten 45 proving decisive in a low scoring contest at the Queen's Park Oval.
Sri Lanka's Kumar Sangakkara struck a fine 71 in a 122 run partnership with Lahiru Thirimanne to give them a solid foundation but after he went, with the first ball of the 40th over and his team 174 for four, their innings fell apart with just 27 runs added for the final six wickets.
Slow left-armer Ravindra Jadeja picked up four wickets as he ran through the Sri Lankan lower order, with India finishing off their opponents with seven balls remaining of their allotted 50 overs.
It was a similar story with India's reply - Rohit Sharma was the anchor, making 58, before he was bowled by slow left-armer Rangana Herath.
Suresh Raina made 32 and when he departed in the 35th over India were well on their way at 145 for five.
But Herath picked up three quick wickets, all lbw dismissals, as India slumped before Dhoni took charge.
Last man Ishant Sharma held up his end, taking just two off the penultimate over bowled by Sri Lanka skipper Angelo Mathews and ensuring Dhoni had the chance to finish with a flourish.
Sri Lanka had chosen to use their best finishing bowler Lasith Malinga in the 48th over, with Dhoni taking just two off it, clearly thinking ahead to the final over.
"I think I am blessed with a bit of good cricketing sense," said Dhoni in the post-game ceremony.
"The opposition bowler was not the most experienced in that last over, unlike Malinga, so I thought I would take my chances. I went with a heavy bat and the weight was perfect for slogging," he added.
Mathews blamed the batting collapse for his team's defeat.
"It was a great game. The bowlers showed a lot of character to (try to) defend 200. We lost momentum in our innings and had we played till the end we could have pushed it to 230-240 and that would have been enough".
Dhoni smashed two sixes and a boundary to take India to a thrilling one-wicket victory with two balls to spare in the Tri-series final against Sri Lanka at Queen's Park Oval in Trinidad on Thursday.
Despite not being fully fit, Dhoni kept his cool shunning singles to shepherd the tailenders and bludgeon Eranga in the final over to carry India over the line.
India finished on 203 for nine in 49.4 overs with Dhoni remaining unbeaten on 45 off 52 balls smashing five boundaries and two sixes.
Sri Lanka did well to claw back into the final having to defend a modest total of 201 despite a 122-run stand for the third wicket between Sangakkara (71) and Thirimanne (46).
India were coasting to victory despite losing Dhawan and Kohli early.
Rohit Sharma (58) held the innings together figuring in half century partnerships with Karthik (23) and Raina (32).
But Rohit's dismissal in the 32nd over bowled by a low delivery from left arm spinner Herath triggered a collapse which saw them slump to 167-8 in the 42nd over.
Herath who finished with four for 20 led Sri Lanka's fight back by trapping Jadeja and Ashwin in successive balls.
Malinga who went for 58 in his 10 overs trapped Bhuvneshwar Kumar.
But ably supported by Vinay Kumar and Ishant Sharma, Dhoni timed his assault perfectly to ensure another memorable triumph for India.
India are 187-9 in 49 overs needing 15 off the last over with Dhoni on strike and Eranga to bowl.
Mathews bowls the 49th over to Sharma.
India 185-9 in 48 overs and need 17 off 12 balls with Sharma on strike.
Malinga to bowl the 48th over with Dhoni on strike.
India are 183-9 iin 47 with Dhoni on strike and need 19 off 18 balls.
Ishant Sharma is the new batsman but Dhoni has crossed and take strike.
Mathews strikes as Vinay Kumar gives a skier to Senanayake. Ind 182-9.
R Vinay Kumar c sub (Senanayake) b Mathews 5 (16b 0x4 0x6)
Eranga keeps it tight as India get three runsin the 46th over. Ind 181-8 in 46 overs.
Vinay Kumar takes a couple off Mathews who bowls a good over. Ind 178-8 in 45 overs.
Malinga bowls an excellent over keeping conceding just a leg bye and keeping Dhoni quiet. Ind 176-8 in 44 overs.
India need 27 from 42 balls. Ind 175-8 in 43 overs.
Interruption in play after a bottle of water has been thrown at Malinga.
Sri Lanka need two wickets while India need 35 runs to win.
Malinga strikes a crucial blow trapping Kumar with a slow yorker. Ind 167-8.
B Kumar lbw b Malinga 0 (15b 0x4 0x6)
Lakmal bowls a maiden to Kumar to complete his superb spell with figures of 10-0-33-1. Ind 165-7 in 41 overs.
Sri Lanka restricted India to 19 for the loss of two wickets in the batting Powerplay.
Dhoni gets another boundary edging Malinga past the vacant slip. Ind 165-7 in 40 overs.
Dhoni swats a low full toss from Malinga to the midwicket boundary.
Dhoni gets a boundary off a thick outside edge off Lakmal. Ind 157-7 in 39 overs.
Kumar averts the hat-trick as Herath complete an excellent spell of four for 20. Ind 152-7 in 38 overs.
Herath has bowled Sri Lanka back into the game with a double strike trapping Jadeja and Ashwin leg before. Ind 152-7.
R Ashwin lbw b Herath 0 (1b 0x4 0x6)
Sri Lanka have bounced back into contention.
Herath strikes trapping Jadeja leg before. Ind 152-6.
R Jadeja lbw b Herath 5 (14b 0x4 0x6)
Lakmal strikes as Raina slashes and gets an outside edge to be caught behind by Sangakkara. Ind 145-5.
S Raina c Sangakkara b Lakmal 32 (27b 1x4 1x6)
Herath strikes with the first delivery after the drinks interval castling Rohit with a ball that kept low. Ind 139-4.
R Sharma b Herath 58 (89b 5x4 1x6)
Rohit cuts a wide delivery from Eranga to the point boundary.
The 50 partnership between Rohit and Raina for the fourth wicket comes off just 42 balls.
Raina lofts Lakmal back over his head for a towering six. Ind 127-3 in 30 overs.
Rohit completes his 17th ODI half century off 80 balls.
Rohit slams a couple of boundaries off Malinga whose six overs have gone for 46. Ind 111-3 in 28 overs.
Rohit plunders another boundary off Malinga.
Herath bowls a maiden to Sharma. Ind 100-3 in 27 overs.
Raina brings up the 100 of the innings by cracking Mathews for a boundary. Ind 100-3 in 26 overs.
Rohit hooks a bouncer from Mathews to fine leg.
Mahela takes a brilliant catch at slip latching onto a fierce driven edge of Herath. Ind 77-3 in 23 overs.
D Karthik c Jayawardene b Herath 23 (37b 3x4 0x6)
Karthik punches Malinga to mid on for another boundary. Ind 76-2 in 22 overs.
Karthik cracks consecutive boundaries off Malinga whose four overs have gone for 27. Ind 66-2 in 20 overs.
Malinga strays down the leg side and Karthik clips him to the square leg fence.
Karthik edges Malinga between the keeper and slip for a boundary.
Rohit slices Herath past point for a boundary. Ind 55-2 in 19 overs.
Rohit gives himself room and smashes a six off Malinga over point.
Eranga strikes again finding the outside edge of Kohli's bat with Sangakkara doing the rest. Ind 27-2.
V Kohli c Sangakkara b Eranga 2 (5b 0x4 0x6)
Eranga strikes producing a snorter which got the shoulder of Dhawan's bat to be caught behind by Sangakkara. Ind 23-1.
S Dhawan c Sangakkara b Eranga 16 (35b 2x4 0x6)
Dhawan gets another boundary off Eranga with a classic cover drive.
Dhawan hits the first boundary of the innings flicking Eranga to the fine leg fence.
Eranga opens the attack with Rohit Sharma taking strike.
Sri Lanka suffered a sensational collapse losing their last eight wickets for 30 runs to be all out for 201 in 48.5 overs after being put into bat by India.
They were got off to a steady start with despite losing openers Tharanga and Mahela.
A magnificent half century by Sangakkara (71) during a 122 run stand for the third wicket with Thirimanne (46) put them in a commanding position.
Sangakkara cracked six boundaries and a six during his knock.
But Thirimanne's dismissal triggered a collapse as wickets fell like nine pins.
Jadeja finished with a haul of four 223 while Kumar, Ishant and Ashwin claimed two wickets apiece.
SRI LANKA INNINGS
Lakmal is the last man out stumped by Dhoni off Jadeja.
S Lakmal st Dhoni b Jadeja 1 (5b 0x4 0x6)
Malinga perishes as Kumar pouches a skier off Jadeja. SL 196-9.
L Malinga c Kumar b Jadeja 0 (2b 0x4 0x6)
Sri Lanka lose their eighth wicket as Dhoni pulls a smart stumping on his second attempt off Jadeja to dismiss Herath. SL 196-8.
R Herath st Dhoni b Jadeja 5 (10b 0x4 0x6)
Sri Lanka are crumbling as Mathews slices to Vinay at third man. SL 193-7.
A Mathews c Vinay Kumar b I Sharma 10 (24b 0x4 0x6)
Lanka collapse as Chandimal falls holing out to Ashwin in the deep off Jadeja. SL 183-6.
D Chandimal c Ashwin b Jadeja 5 (7b 0x4 0x6)
Kusal Perera does not last long jumping out to Ashwin only to be beaten and stumped by Dhoni. SL 176-5.
K Perera st Dhoni b Ashwin 2 (4b 0x4 0x6)
Ashwin gets the big wicket of Sangakkara who holes out to Vinay. SL 174-4.
K Sangakkara c Vinay Kumar b Ashwin 71 (100b 6x4 1x6)
Thirimanne perishes miscuing Ishant to Kumar ending a 122-run stand for the third wicket. SL 171-3.
L Thirimanne c Kumar b I Sharma 46 (72b 4x4 0x6)
Sangakkara is on fire slamming two consecutive boundaries and towering straight six off Ishant.
Sangakkara smashes a boundary off Ashwin over square leg. SL 156-2 in 37 overs.
The 100 partnership between Sangakkara and Thirimanne comes off 133 balls with Thirimanne smashing two consecutive boundaries off Ishant. SL 150-2 in 36 overs.
Thirimanne sweeps Jadeja powerfully for his second boundary. SL 138-2 in 34 overs.
Thirimanne hits a boundary off Raina. SL 100-2 in 28 overs.
Raina drops a straightforward chance off Sangakkara off his own bowling. SL 81-2 in 24 overs.
Ashwin drops Thirimanne at first slip. SL 56-2 in 18 overs.
Kumar strikes again taking the big wicket of Mahela who drives straight to Ashwin at slip. SL 49-2.
M Jayawardene c Ashwin b Kumar 22 (28b 2x4 1x6)
Mahela is in some discomfort having hurt his right thumb attempting a similar shot off Ishant.
Mahela slams the first six of the match hooking a bouncer from Ishant to fine leg.
Mahela lofts Kumar to mid off for his second boundary. SL 42-1 in 12 overs.
Sangakkara gets his first slamming Ishant's first delivery past point. SL 34-1 in 11 overs.
Kumar bowls a maiden over to Mahela. SL 28-1 in 9 overs.
Kumar strikes as Tharanga gets another inside edge which carries to Dhoni. SL 27-1.
U Tharanga c Dhoni b Kumar 16 (29b 3x4 0x6)
Mahela gets his first boundary by lofting Vinay. SL 27-0 in 6 overs.
Tharanga gets another one to the fine leg boundary off a wayward Kumar. SL 21-0 in 5 overs.
Tharanga gets another boundary off an inside edge past the keeper. SL 15-0 in 3 overs.
Vinay Kumar is sharing the new ball with Kumar.
Tharanga hits the first boundary of the final to fine leg off Kumar.
Bhuvneshwar to open the attack as Tharanga and Mahela take strike.
Murali Vijay has given way to Dhoni while Umesh Yadav has been replaced by Vinay Kumar.
Sri Lanka have made two changes with all-rounder Suranga Lakmal being flown in to replace Dilhara Lokuhettige while Kusal Perera comes in for Jeevan Mendis.
India - S Dhawan, R Sharma, V Kohli, D Karthik, S Raina, MS Dhoni, R Jadeja, R Ashwin, B Kumar, I Sharma, Vinay Kumar
Sri Lanka - M Jayawardene, U Tharanga, K Sangakkara, D Chandimal, A Mathews, L Thirimanne, K Perera, R Herath, L Malinga, S Eranga, S Lakmal
India's lucky talisman Dhoni has won the toss and put Sri Lanka into bat in the final at Queen's Park Oval in Trinidad on Thursday.
The good news for India is that Dhoni who was laid low by a hamstring injury is fit to lead the side.
The title clash between India and Sri Lanka in the Caribbean Tri-series will be the first between them since the 2011 World Cup final.
Former Sri Lanka captain Mahela Jayawardene will play his 400th ODI in the Tri-series final against India at Queen's Park Oval in Trindad.
The 36 year-old batsman will become only the third cricketer and second Sri Lankan to reach this milestone after Sanath Jayasuriya and Sachin Tendulkar.