Four half centuries gave hints he had something about him; today he rammed home his case with an innings of positivity and style.
There was crunch in his drives, he swept assertively, was happy to ramp short balls over the slips and backed himself with his shot selection.
"I guess I always look to be positive and be really decisive in my decision-making. Today more so than I have been in the past," Nicholls, 25, said.
"The message from Hess (coach Mike Hesson) was to be really confident in my game and that's something I'm looking to do on a consistent basis."
If you batted any length of time today there would be the occasional error, such was the nature of the seaming pitch.
But Nicholls stayed on message and got a fabulous reward.
"It was probably a bit of a relief really," he said of reaching his century, with a vigorous pull to the square leg fence and a chance to celebrate in front of his parents Rick and Janet and brothers Andrew and Willy.
"It was nice to get through that milestone and contribute to the team total. I had a bit of luck in the nineties but that's the way it goes but I was pretty happy with how I went about my business."
He tried to cash in whenever the bowlers strayed off line, to put some pressure back on them. But this was an innings New Zealand desperately needed and it won't hurt Nicholls' self belief either.
He insists he'd felt no pressure to perform.
"There's always people knocking down the door and always that speculation about your spot. I just tried to stay really clear on what I'm doing.
"I've had great support from the group, giving me a lot of confidence and keep reinforcing to go and play my natural game. Just control what I can control."
