The hosts held India to 190-9 in their 20 overs even though the Asian side got off to good start as openers Virat Kohli and Shikhar Dhawan put on 64 in just 5.3 overs.
However, medium-pacer Kesrick Williams returned figures of 2/42 in the middle overs while Jerome Taylor also got two scalps to peg India back on a favourable batting wicket.
The Windies then raced to their target with nine balls to spare and only one wicket down thanks to a century from Evin Lewis, who stuck an unbeaten 125 off 69 balls.
Brathwaite said after the game: “It was a very good wicket, but we did very well to keep them to 190, especially after the start they had.
“Kesrick [Williams] had two very important strikes in the sixth over and then when Jerome Taylor came back and finished, he brought us back into the game.
“We all thought that 190 was 20 runs short and then the batters proved their worth.”