Rock solid Cheteshwar Pujara stroked his third century of the summer to put India in a commanding position in the decisive fourth Test as they eye a historic series win in Australia.
At stumps on day one, they were 303 for four with the rock-like Pujara unbeaten on 130 and Hanuma Vihari on 39. Mayank Agarwal made 77 with Josh Hazlewood the best of the bowlers with 2-51.
After toiling on a hot Sydney day, Australia were rewarded with the wickets of KL Rahul, Agarwal, Virat Kohli and Ajinkya Rahane, but despite a five-pronged attack the key scalp of Pujara remained elusive.
The visitors lead the series 2-1 after winning the opening clash in Adelaide and the third one in MCG. Australia claimed victory in the second Test at Perth.
If India, the world's top-ranked Test side, win or draw in Sydney they will clinch their first-ever series in Australia since they began touring Down Under in 1947-48.
Kohli again won the toss with Rahul back in the team to open with Agarwal and Vihari dropping to number six to cover for the unavailable Rohit Sharma.
Australia got an early breakthrough with Josh Hazlewood luring Rahul into a defensive shot outside off stump that took an edge and carried to Shaun Marsh at first slip.
But that only brought the stoic Pujara to the crease and like he has done all series, the veteran dug in and defied the new ball.
In another innings of patience and concentration, he slowly picked off runs to bring up his 18th Test century from 199 balls, with 13 boundaries.
The methodical 30-year-old has been by far the best batsman from either side across the series and his ton followed a stellar 123 in the first Test in Adelaide and 106 in the third Test at Melbourne.
Playing in only his second Test, the Bangalore-born Agarwal was also impressive.
He was targeted with bouncers and struck on the helmet but held firm, reinforcing his credentials after a solid debut in Melbourne.
He worked hard to make his second Test 50 in only three innings by caressing a Mitchell Starc delivery through the covers for four.
But he began to open up with the bat and after hitting Nathan Lyon for six to bring up his highest Test score of 7 and attempted to do the same from the next delivery and was caught by Starc at long-on.
Master batsman Kohli was welcomed by boos from a section of the crowd and immediately silenced them with an exquisite four off Hazlewood.
But after a restrained 23, Hazlewood bagged him in the first over after tea when a leg-side delivery flicked off his glove to Tim Paine behind the stumps.
Vice-captain Ajinkya Rahane looked good in making his way to 18, but a Starc bouncer caught him off guard and it too caught his glove for Paine to take an overhead catch.
When Australia bat, they will have a new look opening pair with Usman Khawaja padding up with Marcus Harris after the underperforming Aaron Finch was axed.
In a surprise throw of the dice, leg-spinning all-rounder Marnus Labuschagne was called up and will come in at three.
Mitch Marsh was also dropped with Peter Handscomb back to counter India's two spinners -- Kuldeep Yadav and Ravindra Jadeja.