In reply, opener Cameron Green put India on the back foot with his 30-ball 61 before Matthew Wade (45 not out off 21) took the visitors over the line with four balls to spare. With the win, Australia took a 1-0 lead in the three-match series.
Earlier, Rahul (55 off 35 balls) scored his second consecutive fifty which included four boundaries and three maximums.
The in-form Pandya pummelled the visiting bowlers into submission with his unbeaten 30-ball 71.
The all-rounder smashed the ball seven times to the fence and five times over it to take India over the 200-run mark.
For Australia, medium pacer Nathan Ellis 3/30 was the pick of the bowlers.
Brief Scores:
India 208/6 in 20 overs (Hardik Pandya 71 not out, KL Rahul 55; Nathan Elis 3/30, Josh Hazlewood 2/39) Australia: 211/6 in 19.2 over (Cameron Green 61, Matthew Wade 45 not out; Axar Patel 3/17)