India shrugged off the absence of captain Jasprit Bumrah to dismiss Australia for 181 to reach 141-6 for a total lead of 145 on a remarkable second day of the finely balanced fifth Test on Saturday.
On a day of high drama at the sun-drenched Sydney Cricket Ground, Bumrah took the first wicket of India's road trip but left with the team doctor shortly after lunch due to back spasms.
Prasidh Krishna (3-42), Mohammed Siraj (3-51) and Nitish Kumar Reddy stepped into the considerable bowling void left by their captain to dismantle Australia and fire India to a slender four-run first innings lead at tea.
There was still plenty of spice in the wicket though, with paceman Scott Boland taking 4-42 in the final session to add to his four-wicket haul on Friday as Australia chipped away at the top of India's batting and dug deep into the middle order.
Among others, Boland removed Indian skipper Virat Kohli in Sydney
Rishabh Pant threw off the shackles and produced some outstanding knocks in a stunning 28-ball half-century to stem the rot, but he too departed for 61 in the final hour, Australian skipper Pat Cummins claiming his 14th wicket of the day.
There was still time for Boland to claim his fourth victim in the form of Nitish Kumar Reddy, leaving Ravindra Jadeja, not out, and Washington Sundar, unbeaten on six, at the end of the game.
The sun-soaked crowd of 47,257 in Sydney certainly got their money's worth as the momentum shifted back and forth as it had in the series, which Australia lead 2-1.
India captain and star bowler Jasprit Bumrah was forced off with a back spasm on the second day
Debutant all-rounder Beau Webster, whose 57 was Australia's highest score, drew cheers to the rafters for his half-century and again when he removed Shubman Gill for 13 later in the day to claim his first Test wicket.
Virat Kohli, who stood as India's captain after Bumrah's departure, was booed all the way for what was likely to be his last innings in Australia, and was cheered back to the boundary rope after being caught in the slips by Boland for a timid six.
Boland is fast becoming a cult hero in Australia, and perhaps the loudest roar came when he hit a peach of a delivery to remove opener Yashasvi Jaiswal off stump to end a promising innings of 22.
The Indian supporters also had plenty to cheer about, starting with Bumrah's dismissal of Marnus Labuschagne in the morning session to take his tally in the series to 32 wickets at an average of 13.06.
India captain Rohit Sharma walks out for the fifth and final Test against Australia in Sydney
Krishna also flew the flags for India when Steve Smith was caught in the slips for 33 to break a fifth-wicket partnership of 57 with Webster to leave the former Australia captain five short of 10,000 Test runs.
India, who dropped captain Rohit Sharma in the match, must win in Sydney to salvage the series and retain the Border-Gavaskar trophy.
Bumrah's back spasm may rule him out of the fifth Test
India could be without Bumrah for the rest of the fifth Test against Australia after he left the Sydney Cricket Ground for a scan on a back problem on day two on Saturday.
The fast bowler, who was by far the most influential player in the five-match series, left the field with the Indian team doctor about an hour after the lunch break.
“He had a spasm in his back,” teammate Prasidh Krishna told reporters after the game.
“He has gone for a scan and the medical team is monitoring him, so we will know whenever the medical team hear from us.
Bumrah, India's leading man and best player in the series, is now in doubt for the remainder of the fifth Test
“No matter who is leading us as a team, I think we are very well prepared as a bowling unit. The plan was pretty clear even when Bumrah wasn't there.”
Krishna took 3-42 as India bowled out Australia for 181 on Saturday, but they were just 145 runs ahead at the end of the game with four wickets in hand, three if Bumrah can't bat.
His absence would be even more noticeable if Australia were chasing a relatively small winning target, given that the skipper has taken 32 wickets at an average of 13.06 so far in the series.
“If he wasn't there, India would have to come up with a new plan,” Australia coach Andrew McDonald said.
“He's the leading wicket-taker in the series, so you'd say that would be of little use to us. He can bowl on any surface, anywhere. He's a threat anytime. We knew going into the series that he player an incredibly talented bowler.”