NATHAN Lyon single-handedly turned the Dharamsala decider on its head to send one of the most epic series in Test history down to the wire.
The Australian spinner with a heart as ferocious as his surname ripped through the Indian middle-order with an inspiring four-wicket masterclass which all came in a hurry in a thrilling final session.
India had spent much of day two patiently grinding Australia into the dirt, but after the Lyon blitzkrieg the hosts went to stumps 6-248 and still trailing on the first innings by 52 runs.
If not for a deflating drop from Matt Renshaw at first slip late in the day, Pat Cummins could have swung an even battle firmly into the tourist's favour.
Australia may still live to regret blowing the chance at posting a knockout total on day one, but when Lyon snared danger man Cheteshwar Pujara and Karun Nair in the space of 11 balls, all the pressure suddenly went on India's tail to compensate for going into the all-or-nothing Test a batsman short.
"We're quite positive. It's an unbelievable feeling to be pretty evenly poised after day two," said Lyon.
"I know probably left a few runs out there (batting), but to have them 6-240 odd I am quite happy to be honest. Coming over here everyone wrote us off and to be in this position in the last Test with pressure slightly on India is fantastic.
"Hopefully (batting last) is going to be a massive challenge for them, but that really depends on how long we bat for and how many runs we can set them.
"We believe we're good enough."
yon said the secret behind his own haul of 4-67 was treating the Dharamsala deck like he would an Australian pitch, using bounce to his advantage.
"After bowling a couple of overs before lunch I sat down and thought about what it (pitch) is similar to and it was closer to a home wicket where the bounce is my biggest weapon," he said.
"That's where I am getting guys caught at bat pad and slips. I went back to how I bowl which is probably how I should bowl.
"I should just go out there and back my skill and enjoy the challenge of bowling to the best side in the world in their home conditions."
Some late hitting from maverick spinner Ravi Jadeja added salt to the wound of Renshaw's put down of Wriddhiman Saha on 9, but blazing quicks Cummins and Josh Hazlewood will launch off on day three with a new ball, some widening cracks and a second wind.
Lyon looked like being the hero of Bangalore when he routed India with career-best figures of 8-50, only for Australia to slump to defeat in the second Test.
But Sunday night's brilliant spell could prove the definitive moment of his career if Australia is good enough to back it up.
For 14 overs he went without reward, but in the 61st over Lyon exploded into action, catching Pujara's edge before short leg Peter Handscomb supported with a brilliant diving catch under the helmet.
Pujara (57) batted Australia into submission with a brutal double-century in the third Test, and in a batting line-up missing Virat Kohli, his departure was enormous.
Nair was the latest to be done bat pad off Lyon, but this time keeper Matt Wade wrestled the catch off Handscomb.
Lyon's next major breakthrough came when he got the stand-in captain Ajinkya Rahane for 46 - caught slip by Steve Smith just when the second new ball was about to be due.
Smith shrewdly held off on taking it and was rewarded when Lyon had his next victim, Ravi Ashwin, trapped plumb lbw.
Cummins deserved far better than his figures of 1-59 off 21 overs showed, with the 23-year-old quick causing trouble all day, including a Rahane edge over slips, and then the regulation nick off Saha that should have been swallowed.
His snaring of brickwall-like opener Lokesh Rahul (60) lifted Australia off the canvas just when India were starting to mentally smother them.
Hazlewood was also tradesman-like with figures of 1-40 from 18 overs of toil, but it was Cummins' rampaging performance in only his second Test match back in six years which really turned heads.
Cummins, with a long list of injury setbacks to his name, has precious first-class match practice, but on a massive day of bowling his rapid speeds of 145km/h refused to yield.
India's fourth-wicket fell for 167, a day after Australia's had gone down for 168 - showcasing the gripping nature of this memorable knife's edge series.
A wagging tail from India will give the hosts an enormous boost in this Test, but if Australia can snare early wickets they will surely hold the advantage given they won't have to bat last on a pitch that's showing signs of misbehaving.