Rohit Sharma wins the toss and India will field first.
New Zealand's openers got off to a strong start, racing away to 50 in the fifth over.
Martin Guptill fell for 31 off 15, but became the highest run-scorer in T20 Internationals, surpassing Virat Kohli.
Chahar broke the strong opening stand to bring India back into the game.
India's spinners pulled things back after the powerplay led by R Ashwin, who returned 1-19. Between him and Axar, India's spinners conceded just 45 runs in 8 overs.
India restricted New Zealand to 153, pulling things back beautifully after that explosive powerplay by striking at regular intervals.
KL Rahul and Rohit Sharma made a steady start in a below-par chase.
KL Rahul and Rohit shared a 117-run stand for the opening stand with both getting to their respective fifties.
Despite Southee striking back with three wickets, India wrapped up the game comfortably, in the end, to pick up a 7-wicket win with 17 balls to spare.
India bagged their fifth successive bilateral T20I series win in India.