Ronchi was born in Dannevirke but raised in Australia and saw his chances of an extended run with the Australian side drift away so threw his lot in with New Zealand. He qualified last year and became the first player since South African Kepler Wessels, just over 20 years ago, to represent two major nations.
He's an entertainer with the bat and scores his runs at a naturally high tempo - his strikerate is 118.85 in his 21 ODI innings and an impressive 157.93 in 13 Twenty20 internationals.
"Sometimes I get a bit excited when things are going well. Sometimes I play shots I possibly shouldn't," he admitted. "I'm a massive confidence player so this has been invaluable, really. I'm a lot more relaxed and chilled before I bat.
"If I get into a situation where I think too much about things, that's when I get myself out.
"If I go out, and play it as I see it, things seem to work out."
Ronchi is averaging 50.3 in ODIs this year, which rams home his value at No 7.
The flipside of Friday was Ronchi's miss, when Hashim Amla edged low between Ronchi and first slip when the champion South African batsman was on seven. Neither player moved. Amla went on to make 119.
"You think about it for a while afterwards as you see him making runs," Ronchi said. "It could have changed the game but you just have to put it behind you."
New Zealand are presently well served with wicketkeepers, with BJ Watling among the most proficient test glovemen and Ronchi, usually slick behind the stumps and with a batting approach ideally suited to the limited-overs formats.
"He's a great guy to have within the group, loves representing New Zealand," captain Brendon McCullum said. "To see him come out and back up his [Tuesday] performance, and in the manner he plays the game, is fantastic so hopefully it gives him confidence that he belongs at international level."
South Africa have lost left-arm spinner Aaron Phangiso for the rest of their Australasian tour. Phangiso has sprained a finger on his left hand and is out of action for four to six weeks. Another left-arm spinner, Robin Peterson, will replace him.