Rohit puts on a brave face after India's capitulation in Chennai

Indian captain Rohit Sharma put on a brave face despite his team's 21-run defeat to Australia in the ODI series decider at Chennai on Wednesday.

Leg-spinner Adam Zampa took four wickets as Australia managed to defend their total of 269 on a slow wickets, inflicting painful series on the home team just six months before the start of the one-day World Cup in India.

Electing to bat, Australia could not capitalise on a strong start and was bowled out for 269 in 49 overs on a slow track at the MA Chidambaram Stadium.

Their bowlers, led by Zampa, did an excellent job defending the total and bowled out India for 248 in 49.1 overs as Australia exacted a modicum of revenge after losing the four-Test series 2-1.

While Zampa was the pick of the Australia bowlers, left-arm spinner Ashton Agar turned the match on its head by removing Virat Kohli, whose 54 was the highest score by a batsman from either side, and Suryakumar Yadav in successive deliveries.

It was Suryakumar's third straight golden duck in the series.

For the hosts, Hardik Pandya claimed bowling figures of 3-44 and made a run-a-ball 40 but it was not enough to avoid India's first series loss on home soil since Aaron Finch's Australia beat them in 2019.

India had gone into the series with great momentum, having whitewashed Sri Lanka and New Zealand in the ODIs early this year.

But Australia proved to be a much bigger challenge for the home team.

"The nine ODIs we have played since January, we can take a lot of positives from that," skipper Rohit said after losing the match on Wednesday.

"Today it is a collective failure. In five months' time, we'll be playing in these conditions. You've got to give credit to the Australians as well."

The Indian captain felt the result would have been different if his batsmen had built good partnerships.

"I don't think it was too many runs. The wicket was a little challenging towards the second half. I don't think we batted well," he said.

"Partnerships are crucial, and we failed to do that today. The mode of dismissals... you are born and brought up on these wickets. Sometimes you need to apply yourself, and give yourself a chance.

"It was important for one batter to carry on and take the game deep. But all of us were trying our best; it just didn't happen."

Australia recalled fit-again David Warner but the in-form Mitchell Marsh combined with Travis Head at the top of their batting order to give the touring side another blazing start.

Australia raced to 68 for no loss in the 11th over and Head, who made 33, got a reprieve after Shubman Gill dropped him at deep square leg.

Pandya removed Head, Steve Smith, and Marsh (47) to peg back Australia.

Batting at number four, Warner made 23 before Kuldeep Yadav wrecked Australia's middle order.

The left-arm unorthodox spinner dismissed Warner, Marnus Labuschagne and Alex Carey (38) but Australia's lower order provided crucial runs even though they could not last their full quota of 50 overs.

India also began briskly with Rohit Sharma (30) and Gill (37) playing a few attractive shots.

Kohli tried to forge partnerships with KL Rahul (32) and with Pandya but he looked tired by the end.