The release of Harry Potter and the Cursed Child in New Zealand was timed to coincide with the book's worldwide publication, with fans getting their copies at 11.01am.
Harry Potter fans have already started speed reading and blogging about the next instalment of the boy wizard's story.
The owner of the Dorothy Butler Bookshop in Ponsonby, Helen Wadsworth, was overwhelmed by how much interest there still is in Harry Potter.
"Amazingly surprised - really didn't expect that many people to come. I think we may be sold out! Luckily we've got a box coming next week but - certainly didn't expect this number of people."
About 60 children attended the launch of the book at the Dorothy Butler Bookshop in Auckland this morning.
The latest book is the script of the West End play, which had its gala launch in London overnight. It tells the story of Harry Potter and his friends 19 years after the last book ended.
Speaking at the gala opening, creator J.K. Rowling said it would give fans something special.
Asked whether the stage production and the publication of its script heralds a new phase of stories, Ms Rowling said:
"No. No. He goes on a very big journey during these two plays and then, yeah, I think we're done.
"This is the next generation, you know. So, I'm thrilled to see it realised so beautifully but, no, Harry is done now."
Ms Rowling said it was not a difficult decision to put her Potter creation on stage thanks to producer Sonia Friedman's vision for the show.
"(It) chimed perfectly with the material I had about the next generation and I could see it would work perfectly. So, I never wanted to write another novel, but this will give the fans something special."
Based on an idea by the British author and Potter creator, the play and book feature a grown-up Potter as an overworked employee of the Ministry of Magic and father of three, who is grappling with his past.
Whitcoulls head of books Joan MacKenzie said the different format was unlikely to deter fans.
"I do believe that what the Harry fan club wants is more about what's happened to him in the intervening years, and all of that content is going to be there.
"So I think for anyone who is genuinely interested in the Harry Potter story, it's something that they'll be wanting."
Ms MacKenzie said Whitcoulls wouldn't sell as many copies of The Cursed Child as the final Harry Potter novel, but it was still likely to be the biggest selling book of this year.
The play, which is sold out through May 2017, opens ahead of the November movie version of Rowling's Potter spinoff book Fantastic Beasts and Where to Find Them.
- Reuters / RNZ News