Set a target of 106 to win the match and with it the series, India were 19 for no loss at stumps, needing another 87.
It was simply his day as the three wickets that followed was to show. If you noticed, they had lost three wickets before the deficit was erased, so it was crucial.
In the space of six overs at the start of the innings, David Warner, Smith and Matt Renshaw were all back in the sheds, and before Australia had even got their noses in front.
Earlier, the record was in name of India's all-rounder Kapil Dev and Australian speedster Mitchell Johnson.
Cheteshwar Pujara has been the bedrock of India's marathon 13-Test home season.
In the bowling table, Umesh Yadav has also a achieved career-high ranking. He had refrained from using O'Keefe while Jadeja was at the crease, a measure of the respect Australia had for the left-hander's potential to score quickly.
Protocol dictates they are turned down between balls.
The incident took place in the 33rd over of Australia's second innings after Maxwell was adjudged LBW by South African umpire Marais Erasmus.
Jadeja was hit on the helmet after deflecting a ball from Pat Cummins, who peppered the batsman with short deliveries.
It mattered little though, with the final wicket of Josh Hazlewood falling two balls later, leaving Australia with the prevailing feeling that they'd come so close, yet so far. He achieved fair bit of success as a bowler but never got the due for his efforts.
Umesh Yadav with his 17 wickets was another man to impress in this series. He had Kuldeep caught at deep backward square leg on the sweep with his first ball. He will nearly certainly finish the leading wicket-taker of the series with 25 scalps.
They would have expected a few hard overs from the pacemen but not the fusillade fired down by Bhuvneshwar and Umesh that did for Warner, Smith and Renshaw. But after picking just 4 wickets in his first five Test matches, the then 20-year old was dropped from the team.
Smith finished the series as the highest run-getter with 499 runs and is the only current cricketer to have a career Test batting average of above 60.
Every time Australia - tipped to lose 4-0 - has been knocked to the canvas this series, they've gotten up swinging - right up until the morning when Cummins reined in India's wagging tail to restrict the first innings deficit to a very manageable 32.