As the final vote was announced Robyn Paterson opened a small velvet box. With confetti falling and champagne glasses clinking, she became engaged to her girlfriend of 15 years.
Paula Boock's eyes welled with tears as the ruby ring was slipped on to her finger, formalising a relationship every couple in New Zealand was legally entitled to.
"It will mean the most to our 8-year-old daughter," said Ms Paterson. "For her, it means her parents can have a relationship like all the other kids in her class.
"We have been together for 15 years and can finally formalise that and have a marriage like my sister and my brother have."
Ms Boock said: "It means I can be like everyone else, I can marry the person that I love."
The couple were among hundreds packed into Caluzzi Restaurant and Bar on Auckland's Karangahape Rd. The crowd spilled on to the footpath outside, but all eyes were glued to a TV screen broadcasting live from Parliament.
In Christchurch, TV presenter Alison Mau and her partner Karleen Edmonds gathered at the Pegasus Arms where musician Anika Moa was performing to celebrate the passing of the bill.
Ms Moa, who is in a civil union, raised the possibility of marriage while on stage, while an excited Ms Mau tweeted: "Tonight I'll know whether I can marry my beautiful fiancee. What a great night this is going to be."
An hour after the bill was passed, Ms Edmonds tweeted: "Guess what everyone! We WILL be getting married in NZ this year! Yay!!"
In Auckland, hundreds of students gathered in Shadows Bar at the University of Auckland, where a large banner emblazoned with the slogan "no freedom 'til we're equal" was illuminated by a full-wall projection of the coverage.
"It's an important moment in New Zealand history," said second-year law and arts student Tim Lamussa, 20. "It's something that our children and grandchildren will look back on and think it strange there was a time where people couldn't get married to anyone that they wanted."
Auckland University Student Association Queer Rights officer Levi Joule said the number of heterosexual-identifying students in attendance showed acceptance. "It's super exciting. All these people in one room that are really passionate about equality."
More than 100 same-sex marriage supporters gathered at the San Francisco Bath House bar on Wellington's Cuba St to watch the vote and await the arrival of Louisa Wall.
Scott Summerfield, 22, said the atmosphere had been great: "It really feels great to be gay and alive in New Zealand at the moment."