Australia skipper Steve Smith blamed his team's poor decision-making under pressure after their 4-1 loss to India in the one-day internationals.
The visitors suffered a seven-wicket reverse in the final ODI in Nagpur on Sunday to slip to third in the world rankings. They started the series in second spot.
The latest defeat was Australia's 12th loss in their past 15 ODIs away from home – a worrying loss of form for the 2015 World Cup winners, and just two months ahead of a home Ashes series against England.
"We're just not taking our words out in the middle and doing it with actions. We have glimpses of it and we play well in periods and then we just get ourselves in trouble," Smith told reporters in Nagpur.
"Probably from poor decision-making under pressure, that's what I probably put it down to. That's something that we need to improve on because it's not good enough."
Australia, who came to India off the back of a drawn Test series in Bangladesh that ended 1-1, failed to capitalise on favourable positions throughout their four losses.
The visitors allowed India to reach 7-281 after having them reeling at 5-87 in the first ODI. The Australia batsmen also faltered against India's wrist spinners.
"Probably lacking consistency with the bat I'd say ... I think we're losing wickets in clumps very consistently and that's not good enough," said Smith.
"We probably didn't adapt as well as we would have liked."
Top Australian batsmen were guilty of not converting their starts into bigger scores, costing the visitors against a formidable Indian side.
Smith's own form with the bat was not up to his usual high standards in the five matches, scoring 142 runs with two half-centuries. David Warner and Aaron Finch were the only Australian batsmen to make centuries.
"I wasn't feeling great at the start of the series to be honest. I wasn't holding the bat the way I would have liked to," said Smith.
"As the leader of the team it's been disappointing but I guess sometimes that's cricket. You have those periods where you're not getting the scores you like.
"It's something hopefully I can turn around and hopefully contribute in the T20s."
Smith and Warner both played their 100th ODIs in the series. Warner debuted in 2009, Smith in 2010.
Australia now head to Ranchi for the three-match Twenty20 series starting Saturday. The second and third T20s will be played on October 10 and 13 in Guwahati and Hyderabad.
Australia's Qantas Tour of India
Australia ODI squad: Steve Smith (c), David Warner, Ashton Agar, Hilton Cartwright, Nathan Coulter-Nile, Patrick Cummins, James Faulkner, Aaron Finch, Peter Handscomb, Travis Head, Glenn Maxwell, Kane Richardson, Marcus Stoinis, Matthew Wade, Adam Zampa.
Australia T20 squad: Steve Smith (c), David Warner, Jason Behrendorff, Dan Christian, Nathan Coulter-Nile, Aaron Finch, Travis Head, Moises Henriques, Glenn Maxwell, Tim Paine, Kane Richardson, Adam Zampa.
India ODI squad: Virat Kohli (c), Rohit Sharma (vc), KL Rahul, Manish Pandey, Kedar Jadhav, Ajinkya Rahane, MS Dhoni (wk), Hardik Pandya, Axar Patel, Kuldeep Yadav, Yuzvendra Chahal, Jasprit Bumrah, Bhuvneshwar Kumar, Umesh Yadav, Mohammed Shami.
September 17: India won by 26 runs (DLS Method)
September 21: India won by 50 runs
September 24: India won by five wickets
September 28: Australia won by 21 runs
October 1: India won by seven wickets
October 7: JSCA International Stadium, Ranchi
October 10: Barsapara Stadium, Guwahati
October 13: Rajiv Gandhi International Stadium, Hyderabad