An explosive Rishabh Pant slammed the second-fastest Indian Test half-century on Saturday to drive the visitors to a 145-run lead with four wickets left after an intense Day 2.

At Stumps on Day 2, India were 141-6 after they dismissed Australia for 181 in reply to their first-innings 185.

Australia lead the series 2-1 with India needing to win at the Sydney Cricket Ground to retain the Border-Gavaskar Trophy.

Pant signalled his intent by plundering a six on his first ball and reached 50 after just 29 deliveries with another big shot that cleared the ropes.

Only his 28-ball half-century against Sri Lanka in 2022 was faster for India.

He was finally dismissed for 61 off 33 by Pat Cummins, but Scott Boland was India’s main tormentor, taking 4-42.

Pant’s exploits set up an exciting finale, amid doubts over whether skipper Jasprit Bumrah will take any further part.

He left the field after bowling one over following lunch and was driven from the SCG, likely for hospital scans. Bumrah was seen returning before stumps.

In his absence, Prasidh Krishna (3-42), Mohammed Siraj (3-51) and Nitish Kumar Reddy (2-32) stepped up to fill the void and dismiss Australia after they resumed on 9-1.

Yashasvi Jaiswal got India’s second innings off with a bang, crunching four boundaries from the first over by Mitchell Starc.

But the opening partnership was quickly shattered when KL Rahul was bowled for 13 by Boland, whose line and length was impeccable.

He pounced again in his next over with a ball that jagged back to deliver the same punishment to Jaiswal (22).

Virat Kohli desperately needed a big score — for himself and the team — but failed to deliver again, perishing in the slips for six with his nemesis Boland once more the destroyer.

It was likely the 36-year-old Kohli’s last Test innings in Australia, with India usually only visiting every four years.

Webster claimed Shubman Gill (13) as his first Test wicket, but at the other end Pant was on a mission until an edge off Cummins carried to wicketkeeper Alex Carey.

Boland claimed his fourth to remove Reddy cheaply.

Australia lost Sam Konstas (23), Marnus Labuschagne (two), Travis Head (four) and Steve Smith (33) before lunch.

In front of his home crowd, Smith looked set to become only the 15th batsman and fourth Australian to reach 10,000 Test runs.

But he was made to wait, five runs short, after Prasidh enticed an edge to Rahul in the slips.

The home side resumed after a dramatic final-ball wicket on Friday when Bumrah — captaining the side after Rohit Sharma was “rested” — had Usman Khawaja caught.

That Australian body blow came two balls after Bumrah and Konstas had a tense exchange.

The 19-year-old Konstas padded up again on seven with new partner Labuschagne, who didn’t last with Bumrah getting the faintest edge to Pant.

A fearless Konstas slammed Bumrah to the boundary, then produced an audacious reverse ramp shot for another four.

But the teenager overplayed his hand and fell to a Siraj outswinger, attempting a drive that flew to Jaiswal at gully.

Siraj removed Head in the same over with another gem to leave Australia at 39-4.

Smith and Webster, who replaced the dropped Mitchell Marsh, began the rebuild before Prasidh dismissed the veteran just before lunch and bowled Carey soon after their return.

India then took 3-4, with Reddy at the forefront, as the tail collapsed.