West Indies chased down a target of 249 with six wickets and nine balls to spare in Ranchi, setting their highest successful T20I run chase.
Shai Hope scored an unbeaten 102 off 45 balls and Sherfane Rutherford added 84 runs off 37 balls, overcoming an early three-wicket burst from Mayank Yadav.
India had earlier posted 249 for five, driven by Sanju Samson's 82 off 41 balls and useful contributions from Ishan Kishan and Tilak Varma.