While Cannavaro had a difficult afternoon at the heart of the Italian defence during the 1-1 draw, Nelsen was superb in the middle of New Zealand's. Even when his less experienced team mates looked ready to buckle in the face of intense Italian pressure, the 32-year-old stood strong.
Nelsen is one of the few New Zealanders to play regularly at the highest level in European club soccer, for Blackburn Rovers in the English premier league.
He said he had tried to use that experience to help the more junior members of the squad.
"The rest of the team don't play against world class players so they don't see that they make a lot of mistakes too and that they're very human," Nelsen said after the match.
"That's what I was trying to tell the boys. Most of our guys are better athletes and when you're a better athlete, you're stronger and faster and you can really do things."
Nelsen was shouting and gesturing at his fellow defenders throughout the game, marshalling them and organising them to combat the Italians.
He fell to the ground just a few minutes from the final whistle, suffering from cramp, put picked himself up to finish.
"Every muscle in my legs cramped, I couldn't even move," he said. "But when you've worked so hard for 85 minutes you're not going to give up in the last five minutes."
Nelsen has been part of the New Zealand set up for over a decade, having made his debut for the All Whites in 1999. He joined Blackburn on a free transfer in 2005 and has been a regular for the English side ever since.
He will lead New Zealand into their final group match against Paraguay in Polokwane on June 24, and said he expected soccer fans around the world to get behind his unfancied side.
"Around the world now, I think New Zealand are everyone's second favourite team," he said. "It's a real Cinderella story.
