When 15 for four at lunch became 25 for five shortly after, it had a familiar feel. After all, 45 at Cape Town last January and 68 at Lord's in May remain fresh in the memory, whatever the fine accomplishments over the past couple of months.
Three early dismissals were due to batsmen showing positive, if poorly-executed, intent. All that raised the thought: did the feathery cushion of a 301-run lead soften the minds to what was required, namely slamming the door shut on India, and in the process removing one of the three results from the equation?
India's tails were up, notably Mohammed Shami, who was outstanding both in pace and line in an opening 10-over spell, which produced three for 30 as the spearhead of a strong collective display.
A good thing, then, that Ross Taylor managed 41 while last pair Neil Wagner and Trent Boult got New Zealand to three figures with what might come to be an important 25-run stand.
The Indian fielding was distinctly sharper yesterday, save another Murali Vijay howler at first slip. It didn't matter as McCullum was out a couple of balls later.
The middle session turned into a tense battle, each run eked out drawing its own applause as New Zealand sought to clamber off the canvas. BJ Watling's 11 in 97 minutes demonstrated his stickability but the tea break did for him, departing along with Ish Sodhi in the first over after the resumption.
Captain McCullum's decision not to enforce the follow on before lunch was the day's major talking point of the day. On the same pitch last March, he decided not to do so against England when holding a 239-run lead and England hung on over the final day, albeit by just a single wicket.
At Dunedin two months ago he also sent the West Indies back in and was criticised as they made over 500. Rain helped them to a draw but on both occasions the batsmen were more difficult to dig out second time around than the gnarliest of roots. Undeterred, McCullum repeated the dose in the second West Indies test in Wellington and had a spectacular reward.
Maybe it was a desire to give the three seamers a decent rest before the second tilt; or a belief that India's class batting group were unlikely to stumble to the same degree when the pitch was expected to be at its best for batting.
The point of deciding whether to enforce a follow on has to be based on how best to further strengthen an already powerful hand.
Should New Zealand go on to win the test, the decision will be lost in time, as opposed to possibly becoming a stick to beat McCullum with.
However, Eden Park rarely breaks up on the fifth day, as New Zealand discovered against England last season. Wagner said the team wholeheartedly supported the decision to bat again: "We'd have taken that lead any day. There was time for the bowlers to freshen up and re-focus on what we need to do," he said.
The veteran left-armer Zaheer Khan said the Indian focus had been on bowling areas, rather than overdo the short-pitched deliveries of the first innings.
"It was a brilliant performance by the bowlers. As a unit we clicked," he said, maintaining that the momentum is decisively with the visitors.
"What got to them was pressure, I guess, and disciplined bowling. I don't think the pitch has changed a great deal - in fact it's got better [for batting]."
McCullum may have been sweating last night over his dropping of Shikhar Dhawan on seven, low at cover in the second over of the chase. The lefthander starts today on 49, with talented Cheteshwar Pujara on 22.
Wagner called it a "bittersweet" day.
"But we're still pretty happy where we're at. The key is to be patient and not go searching. We've still got runs to play with."
Enough, they hope.
