The prince, second in line for the throne, was shown around the stadium by John Waller, chairman of the Eden Park Redevelopment Board, Prime Minister John Key and Auckland Mayor John Banks, who briefed him on plans for the Rugby World Cup and redevelopment of the park.
A number of All Blacks, including Richie McCaw, Ali Williams and Dan Carter, were also on hand to show the prince around.
Williams told NZPA he thought people in New Zealand still cared about the monarchy.
"I think they respect it. As players, we definitely respect it. Prince William likes hanging out with the guys, but I think he's after inside information," Williams joked.
"We don't give him much though," he added.
"He's quite knowledgeable on the rugby game. He doesn't really want to talk about the royal family with me and I don't really want to talk rugby with him, so we found a happy medium and had a good laugh.
"I think that's the name of the game really. We just enjoyed each other's true character. I've enjoyed meeting him every time," he said.
All Blacks captain McCaw said Prince William was just a "genuine bloke".
"I think Kiwis will be intrigued to see him in the country for the next couple of days. There's definitely a lot of respect there.
"It can't be easy being in the position he's in, but he handles himself amazingly well. Underneath all that stuff he has to deal with, he's just a genuine bloke you can have a yarn with," he said.
A lucky team of boys from Pakuranga Rugby Club Under-10s played rugby with All Blacks Williams, Anthony Boric, Jerome Kaino, Joe Racokoko, John Afoa, Keven Mealamu and Tony Woodcock on the newly sown pitch, before they got to meet Prince William himself.
Milan Mann, 9, said it was "pretty cool" to meet Prince William.
"I had lots of fun today and it was great to meet the prince. He has a good accent," he said.
Ryan Wallace, 10, said it was "a once in a lifetime opportunity".
"It's not every day you get to meet a future king, and I got to shake his hand too," he said.
Journalists were under strict instructions to keep 2m away and not to ask Prince William any questions, because he probably wouldn't answer them.
Arthur Edwards, royal photographer for Britain's The Sun newspaper since 1977, was one of the many journalists from overseas who are following Prince William's every move, as he makes his first official visit on behalf of the Queen.
"My schedule is William's schedule. Whatever he does, I do," Edwards said. "I was here in 1983 for when he crawled on the lawn at Government House. I was also here in 2005 when he was here with the Lions, and that was a brilliant tour.
"It was sad towards the end because we had the terrible bombings in London, and we were supposed to go whale watching, but obviously it was all cancelled because of the deaths in London. But I don't remember it for that, I remember it because the girls went crazy for him. As he left the War Memorial in Wellington, I remember girls screaming like he was Elvis or Michael Jackson. It was tremendous," Edwards said.
"He's quite popular here I think. This is the first time ever we've realised the Queen and the Duke can't do the long haul flights for much longer.
"It's a huge responsibility for him. He's been well trained by his father and he couldn't have had a better teacher. I think he'll do a good job, and he realises the responsibility involved.
"New Zealand once was the most loyal to the monarchy of all the Commonwealth countries that I've ever visited. But I think now there's more of a republican view being sought after, and maybe there's time for New Zealand to go their own way, and Australia too. But whatever happens it will be their choice," Mr Edwards said.
Prince William arrived in Auckland this morning and was met by Prime Minister John Key and his wife, Bronagh.
New Zealand Governor General Anand Satyanand was also there to greet him when he landed shortly after 11am.
After his visit to Eden Park, Prince William then went sailing on Waitemata Harbour on the America's Cup yacht NZL40, and he will attend a hangi at Government House tonight.
He will fly to Wellington tomorrow, where he will represent the Queen at the opening of the new Supreme Court building.
Other activities include a wreath laying at the National War Memorial, a barbecue hosted by Mr Key at Premier House and a visit to Wellington Children's Hospital.
Members of the public will have a chance to see Prince William when he does a walkabout after the Supreme Court opening.
Prince William will leave for Australia on Tuesday.
