Virat Kohli returned to form with a classy century as India claimed a thumping win against Australia in their series opener and stand-in skipper Jasprit Bumrah said the veteran batsman's importance to the side cannot be overstated.

India overcame an unpromising start to thrash Australia by 295 runs in the first test at Perth Stadium on Monday, laying down the gauntlet for the rest of the series and putting to bed any question marks about their form.