India vs Australia, 1st Test: How spin & pace exposed Tim Paine's team
Ashwin bowled beautifully to take three wickets, while Ishant Sharma and Jasprit Bumrah grabbed two each.
India vs Australia, 1st Test, Day 2: Australia at 191 for 7
Australia's horror start in the opening Test against India in Adelaide has raised many questions on the host's preparations for the series.
Off-spinner Ravichandran Ashwin bowled beautifully to take three wickets, while Ishant Sharma and Jasprit Bumrah grabbed two each.
Australia were 191 for seven still, 59 runs short of India's modest total of 250 at second day's close.
Australia got off to a horror start with Finch's credentials as an opener again called into question after he was spectacularly bowled without scoring on only the third ball he faced.
Third ball of the innings and a lovely delivery from Sharma took out his middle and off stumps after getting an inside edge as Finch attempted a drive.
Aaron Finch: 0 run off 3 balls.
Marcus Harris looked in good nick and unruffled by the occasion, hitting three fours in his solid 26.
But he was undone by a drifting ball from Ashwin, getting an edge to Murali Vijay at silly mid-off and ending a 45-run partnership with Usman Khawaja.
Debutant opener Harris was quick to blame a "tough" drop-in wicket and worked hard to put a rosy spin on the batsmen's travails.
"It's not as easy as the old Adelaide Oval wicket," said Harris, who was caught in close for 26 after nicking onto his pads.
"We're definitely still 100 percent in the game."
Marcus Harris: 26 runs off 57 balls.
Ashwin's off-spin was causing problems and Marsh needlessly slashed at a wide delivery in the first over after lunch, dragging it onto his wicket.
The woeful shot extended his dire recent Test form and left Australia in trouble at 59-3. Marsh has now slumped to six consecutive single-figure scores, failing to step up in the absence of Smith and Warner.
Shaun Marsh: 2 runs off 19 balls
Ashwin was the star in first Test's second day as he took three crucial wickets to destroy Aussies batting unit.
Usman Khwaja, whose Test preparations were disrupted after the shock arrest of his brother this week for allegedly framing a love-rival with a fake terror plot, was Ashwin's next victim.
Wicketkeeper Rishabh Pant took an excellent catch after a turning ball flicked off Khawaja's glove. He was out for 28 on a review decision.
Usman Khwaja: 28 runs off 125 balls.
Paine to the crease at number seventh spot, but he was unable to stop the rot and added only five runs before becoming Sharma's second scalp.