Root turned his overnight 114 into 226 on day four of the second Test, with his 441-ball innings the longest in his Test career to date.
The captain averaged 27.40 in 2019 heading into the Hamilton Test but says he did not believe he was far away from rediscovering top form.
“I have felt close for a long time, it has been around the corner,” Root told Sky Sports Cricket at stumps at Seddon Park, after New Zealand closed on 96-2 in their second innings to trail England by five runs.
“I had the bit between my teeth when I got going and wanted to make it a real big one and give us an opportunity to win this game.
“I felt pretty good all the way through it. I managed to find a good tempo, was busy, got my feet going, felt like my normal self.
“Even though I didn’t score as freely as I normally would, I felt I was playing in the same sort of manner and let the pitch and situation dictate the rest.”
England led by 101 on first innings after being bowled out for 476 – Root and Ollie Pope (75) putting on 193 for the sixth wicket after the tourists had resumed on 269-5.
Sam Curran and Chris Woakes then picked up a wicket apiece in the final session as the Kiwis slipped to 28-2, only for Kane Williamson (37no) and Ross Taylor (31no) to rebuild with an unbroken stand of 68.
“I thought it might do a little bit more in terms of up and down but it hasn’t seemed to – but we have a couple of wickets and you never know in the morning,” said Root when asked about England’s chances of forcing a win.
“The frustrating thing is the forecast isn’t great, hence why we sped things up at the back-end of our innings. We have given ourselves a chance and if we get a cluster of wickets you never know.
“[Williamson and Taylor] are two very experienced players that you expect a bit of a rearguard from – they know how to play in those situations and on good surfaces you expect a fightback from the No 2 side in the world.
“If we can make an early breakthrough it could get us on a bit of a wicket train because they’re such key figures in their batting line-up. It would give our guys a lot of confidence.”
England will look to beat New Zealand without a front-line spinner having opted to leave out Jack Leach in favour of an all-pace attack – but Root does not feel his side will live to rue that decision.
“We have two part-timers!” the captain added, referring to himself and fellow spinner Joe Denly.
“It hasn’t spun a great deal and it has played pretty nicely against their spinner [Mitchell Santner]. In an ideal world you want a number of different variations but I think we have a couple of guys who can offer that.
“Ultimately, if it goes up and down, the seamers are the ones who are going to take wickets. [We need] one big last push from everyone and to try to come away from here with a levelled up series.”
Will England win the second Test and draw the series? Find out live from 9pm on Monday on Sky Sports Cricket.