India collapsed in the second session against Australia, as they were bowled out for 503 at tea on day three of the second Test in Hyderabad.
The hosts were all out on the stroke of tea to end the first innings with a massive lead of 266 runs, after adding 103 runs in the post-lunch session with the loss of seven wickets.
Glenn Maxwell and Xavier Doherty led the tourists' fightback by taking four and three wickets respectively.
India's lead is largely thanks to a fantastic 370-run partnership between Murali Vijay (167) and Cheteshwar Pujara (204) - the fourth-highest pairing for any wicket for India in Test cricket.
However, Vijay was the first to fall from the duo after being caught by Ed Cowan off the bowling of Maxwell, before the tourists ended Pujara's spell at the crease, after James Pattinson's bowling led to Doherty pulling off a low catch.
Virat Kohli (34) and MS Dhoni (44) were other notable scorers for the hosts, while Sachin Tendulkar was caught out for seven runs.
Australia declared on 237-9 in their first innings.