Usman Khawaja admits Australia blew their chance to level their four-Test series against India following a stunning batting collapse in their six-wicket loss in Delhi.
India's win in the second Test meant the hosts retained the Border-Gavaskar Trophy with an unassailable 2-0 series lead.
Australia began day three in a promising position, holding a 62-run lead with nine wickets in hand in their second innings.
But the wheels began to fall off in the first over of the day, with opener Travis Head out for 43.
Head's dismissal left Australia 2-65, before the tourists lost their next eight wickets with just 48 runs added to their total to be all out for 113 during the morning session.
Player of the match Ravi Jadeja did much of the damage with the ball for India, claiming the superb figures of 7-42, while fellow spinner Ravichandran Ashwin took 3-59.
Chasing 115 for victory, India reached the target for the loss of four wickets.
Khawaja — who was the first Australian dismissal in the second innings on day two — said the Delhi result would "probably hurt a bit more" than the innings defeat in Nagpur in the opening Test.
He said Australia wasted the opportunity to take greater control of the second Test with their poor batting performance on day three.
"Today we had the game in the palm of our hand," Khawaja told ABC Sport.
"Things can happen really quickly in the subcontinent, and we know that, and they did unfortunately. We couldn't string a partnership together."
Aussies 'couldn't do it'
Khawaja said he did not believe Australia needed to set India a mammoth run chase if it was to win in Delhi because of the condition of the pitch.
"I felt after yesterday, we had all the momentum," he said.
"If we could get somewhere around 180-plus [runs ahead] I thought it was almost game over. That's a pretty tough wicket out there but we just couldn't do it."
Khawaja — who scored 81 in the Australia's first innings — said he and his teammates were in a buoyant mood when they arrived at Arun Jaitley Stadium ahead of day three.
"This morning everything felt really good," he said.
"I had a really good feeling about us getting some runs on the board and trying to win this Test match, but you can never get too far ahead of yourself in sport."
Khawaja said while the Australians were ultimately "outclassed" by India in Delhi, he was confident they could bounce back in the third Test, which will be played in Indore next month.
"We probably could have won this Test match but we didn't," he said.
"I'm sure it will drive the boys more than anything."