Tim Southee swings it New Zealand's way after Kane Williamson steadies the ship

As Kane Williamson left the field on the fifth afternoon, taking with him a pitch-perfect innings of 49 from 177 balls that had telegraphed the relentlessness of India's seam attack while at the same time rising above it, he turned to his batting partner Tim Southee and uttered a few pointed words of encouragement. The lead was a slender four runs, with two wickets standing, and more than 40 overs remained scheduled for the day. It didn't take a lip-reader to translate the captain's orders.

For Southee likes to lump it. He has been hitting sixes with a unique alacrity, almost from the day he arrived on the international scene as a precocious 19-year-old, 13 long years ago in Napier. He cracked nine on that final afternoon against England in 2008 - almost exclusively mown over midwicket, as he announced his arrival with a Nathan Astle tribute knock of 77 from 40 balls from No. 10, to cause improbable jitters in a monstrous chase of 553.

The scenario could hardly have been different on this occasion, but the levers remained true. Lump it Southee did, two hulking swings through the line, high over his favoured leg-side, as New Zealand's remarkable tail attempted a repeat of the trick that had set them apart in their home series against India in early 2020.

Southee's six-hitting exploits are well known but bear repetition - his tally is up to 75 now in 79 Tests, and at a ratio of 1 every 27 balls which has no equal in the game. His nearest "rival" by that measure, astonishingly enough, is none other than his new-ball partner and No. 11, Trent Boult, who's picked off 30 to date, at roughly 1 in 40 balls. By contrast, the great Ricky Ponting, whom Southee pulled clear of in his short-but-sharp innings of 30, faced more than 52 overs for each of his 73 thumps over the rope.

But therein lies the difference between great batters and great hitters, for in truth the fireworks didn't quite come off as planned. India's otherwise under-employed spinners picked off the last two wickets for a slender deficit of 32, but given that their own lower order had been docked to the tune of three wickets in four balls in India's first innings, the difference in potential for the spicy end of this contest was plain enough to see, even in a rare passage of accelerated action.

"It was just a bit of reminder to keep going and eke out as many runs as we possibly could," Southee said of his chat with the outgoing Williamson, whose preternatural technique had once again calibrated the risks and rewards throughout a morning session in which New Zealand, trailing by 116 overnight, had a game to lose but nothing yet to win. "It was about trying to hang in with Kane for as long as we could, and once he left, the way that we play our best is with that freedom as bowlers and as tailenders."

Williamson scored 7 from 75 balls before lunch, dogged and dour - occasionally shaking his right elbow which was stiff with cramp, but seemingly untroubled by the left joint that has caused him such bother in recent months. He had never before faced so many balls in a Test innings without reaching a half-century, but the logic to his attrition was indisputable.

"Steady the ship," as the sailor-hat tributes among the Kiwi contingent would put it, let others bat around him during that dicey morning period, in which Mohammad Shami in particular was hounding the edge with a pent-up fury, as he finally earned some reward for his years of toil in English conditions.

"It was crucial," Southee said of Williamson's durability. "It was a tough time this morning, the Indian bowling asked a lot of tough questions and put us under a lot of pressure, and he was able to hang tight and dig deep and battle his way through. He's a class player, and he's got a very sound defence that he was in full trust with."

Williamson began to up his tempo against the new ball, more than doubling this total in his final 36 balls as India's fatigued trio of quicks found their discipline beginning to flag. But it was the men around him who kept nudging the score towards parity - Colin de Grandhomme, whose 80-plus strike rate is up there with Adam Gilchrist and Virender Sehwag, and Kyle Jamieson, whose levers are even more imposing than Southee's, and whose average continues to hover above 40 after another front-dog dominant display.

"You always probably want more than what you got, but it's shaping up for an intriguing day tomorrow," Southee added. "To have two of their more attacking players as well, it's nice to see the back of them."

That's putting it mildly. For it was Southee the bowler who completed the job that Southee the batter had started, prising out the vital scalps of Shubman Gill and Rohit Sharma to a pair of subtly different inswingers - the first with his so-called three-quarter-seam drifter, the second a more simple flipping of the shiny side as Rohit fatefully shouldered arms on a fourth-stump line - to ensure that New Zealand are the only team for whom attack is a broadly risk-free option going into the historic day six.

In the first innings, Southee had bore the brunt of both his victims' pugnacity, as India hurtled off in a 62-run opening stand that was the only moment to date in which New Zealand seemed out of control with the ball. This time he sought to be fuller and more menacing, recognising that the tables had turned since Williamson's morning vigil, and now it was his opponents who had nothing to gain from aggression.

He's always had his outswinger, right from that Napier debut, when four of his five wickets were a consequence of his natural bend - three catches in the cordon plus the prized maiden scalp of Michael Vaughan, pinned lbw by the one that didn't move. By his own admission, the inswinger has been a trickier beast for him to tame down the years, but in arguably the most important Test match of his long and storied career, he chose an opportune moment to confirm his hard-earned mastery.

"As a player you're always looking at different ways to expand your game, and that's been one of the ways I've looked to develop over the last little while," he said. "Especially with the Dukes ball, being able to swing it that a little bit more."

The Gill dismissal was Southee's 600th in all internationals - a milestone he acknowledged was "nice" to have ticked off. But having picked up a five-for in his first Test of this England tour at Lord's, he knows he's in the form to make India's life more uncomfortable yet, as New Zealand seek to turn the screw on a slender lead of 32.

"The Indian side probably had their most challenging period when the ball was slightly older," Southee said. "Hopefully tomorrow morning, it will swing a little bit more and we can ask a few questions early on."