Opening batsman's half century was supported by spinner's four wickets as the hosts stormed to a 93-run win.
Rahul and Chahal guide India to record margin T20 victory against Sri Lanka
Opener Lokesh Rahul's attacking half-century and four wickets by leg-spinner Yuzvendra Chahal powered India to their biggest ever Twenty20 win, outplaying Sri Lanka by 93 runs in the first match on Wednesday.
Chahal returned impressive figures of 4-23 to help dismiss Sri Lanka for 87, in 16 overs, while chasing 181 as the hosts took a 1-0 lead in the three-match series.
India's previous biggest T20 triumph in terms of runs was their 90-run win over England in the 2012 World Cup group match in Colombo.
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Rahul smashed 61 off 48 balls as India posted a challenging 180-3 after being invited to bat first.
But it was Dhoni (39) and Manish Pandey (32) who set up India's big win with their unbeaten 68-run stand for the fourth wicket that lifted the team from 112-3 to put up a challenging total.
Dhoni hit 4 fours and a six during his 22-ball blitz while Pandey also hit the bowlers to all parts of the ground during his 18-ball stay.
Earlier Rahul, who replaced Shikhar Dhawan in the XI, put on a crucial 63-run stand with Shreyas Iyer, who made 24, after India a lost an early wicket.
Angelo Mathews got skipper Rohit Sharma caught at mid-on for 17 to check India's surge after the openers gave the team a brisk start.
Rahul, who hit 7 fours and a six, carried on with his attacking play as he reached his second T20 fifty in 34 balls, prompting skipper Thisara Perera to rotate his bowling options.
The ploy worked as Sri Lanka took two quick wickets including that of Rahul and also managed to stem the flow of runs. Perera bowled Rahul on a well-disguised slower delivery.
But Dhoni and Pandey finished off the innings with a flurry of fours and sixes as India got 66 runs in the last five overs.
In reply, the Sri Lankan batting faltered against the Indian wrist spinners as Upul Tharanga top-scored with 23.
Fast bowler Hardik Pandya claimed three wickets while left-arm unorthodox bowler Kuldeep Yadav picked two.
The second match is scheduled for Friday in Indore.