Bangladesh fast bowler Hasan Mahmud rattled India with four wickets to leave the hosts on 176-6 at tea on the first day of the first Test at Chennai on Thursday.
Hasan vindicated skipper Najmul Hossain Shanto's decision to field first in overcast conditions as he struck early with three wickets and took one more after lunch.
Ravindra Jadeja, on seven, and Ravichandran Ashwin, on 21, were batting at the second break.
The tourists, who come in fresh from a 2-0 sweep in Pakistan, are chasing their first-ever Test win against India.
Mahmud ripped through the Indian top order including skipper Rohit Sharma and Virat Kohli -- both scoring just six runs -- to leave the hosts teetering at 34-3 inside the first hour of play.
Opener Yashasvi Jaiswal, who made 56, put on a 62-run stand with fellow left-hander Rishabh Pant to get some momentum into the Indian innings.
Hasan broke the stand in the third over after lunch when wicketkeeper-batsman Pant, who is playing his first Test after a serious 2022 car crash, was caught behind off a loose shot. He made 39 with six boundaries.
Jaiswal reached his fifty but fell to Bangladesh's new pace sensation Nahid Rana. Spinner Mehidy Hasan Miraz then took down KL Rahul for 16.
Hasan's opening spell of 3-14 put the hosts immediately on the back foot, starting with Rohit caught at second slip.
Shubman Gill survived just eight deliveries before being caught behind for a duck when he attempted a flick down the leg side.
Kohli walked in to loud cheers but the noise soon stopped when the former captain edged a length delivery outside the off-stump from Hasan to wicketkeeper Litton Das.
It was a disappointing outing for Kohli after missing his team's 4-1 home win over England in March due to the birth of his second child.
India are looking to extend their lead at the top of the World Test Championship rankings as they begin a fresh Test season of 10 matches.
The second and final Test starts on September 27 at Kanpur.