As much as the day belonged to the Indian bowling unit for another fired-up show, new captain Rahane deserved equal credit for marshalling his resources to perfection during the 72.3 overs that Australia batted.
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Bumrah (4/56 in 16 overs) and Ashwin (3/35 in 24 overs) were the stars but debutant Mohammed Siraj (2/40 in 15 overs) also did his bit repaying the faith shown in him with wickets of Marnus Labuschagne (48) and Cameron Green (12) with the old ball.
However, the Test series is increasingly looking like Ashwin's paradise as he once again made the opposition's best batsman Steve Smith (0) look ordinary, exploiting the turn and bounce that the first day of the MCG track offered.
It was business as usual for Bumrah as he beat the bat and got those breakthroughs just when it mattered on a pitch that had retained moisture. As it turned out, Rahane didn't lose a bad toss.
The Indian team looked way more galvanised despite being without regular skipper Virat Kohli, who is on paternity leave. Some great catches were taken and the intent was way more visible.
Rahane's first punt was introducing Ashwin inside the first hour of play after Bumrah had forced Joe Burns (0) to nick one to Rishabh Pant.
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Ashwin, who varied the pace of his deliveries cleverly, got some turn and bounce straightaway as he drew Matthew Wade into coming down the track and skying one for India's best fielder Ravindra Jadeja to take a well-judged catch running backwards.
After bowling one that jumped and turned beating Smith and Pant, Ashwin kept the next a tad straighter and the former Australian skipper's glance was pouched by Cheteshwar Pujara at leg gully.
All this while, Bumrah was beating the bat at the other hand.
Interestingly, Rahane didn't give the debutant a single over before lunch break as he knew that Siraj's strength is generating pace and movement with semi-new and old ball.
Siraj initially bowled a bit short at Labuschagne and Travis Head (38 off 92 balls) as they added 86 runs for the fourth wicket.
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It was Bumrah, who provided the post lunch breakthrough with a delivery that held its line and the left-hander's thick edge was taken by Rahane at gully.
Siraj's maiden wicket was a lucky one as the ball was drifting down the leg-side which Labuschagne tried to whip but Gill, stationed at backward square leg, snapped it inches off the ground.
The Hyderabad pacer's second wicket was a much fuller ball with a hint of inward movement that caught Green plumb in-front.
Skipper Tim Paine (13) couldn't script a rescue act like Adelaide as a classical off-break saw him guide one straight into the hands of Hanuma Vihari at backward square leg.
Bumrah didn't take much time after that as he and Ravindra Jadeja (1/15) polished off the tail in a jiffy.
During the final hour of the day, Gill showed what the Indian cricket can expect of him in the new decade. He disolayed positive intent and some dazzling strokes that would certainly leave fans yearning for more in the coming days.
An off-drive off Pat Cummins, a punch through covers and a flick off Starc were exhilarating.
The cover drive off Nathan Lyon had class written all over it.
India trail 0-1 in the series after going down by eight wickets in the opening day-night Test in Adelaide. The visitors were dismissed for their lowest Test score of 36 during that game.
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