Until then, the event had been peaceful, attended by family groups, teenagers drinking alcohol and some gang members.
But in a matter of minutes, it turned ugly.
Faced with a barrage of bottles and rocks, about 20 police tried to stop a fight that broke out with a series of charges and retreats until reinforcements arrived.
When the police ordered the concert to stop at 8.10pm, because the music drowned out their instructions, hundreds of angry music fans ringed the battlefield to cheer on the troublemakers.
By 9pm, 60 police officers were trying to contain the riot and 43 required medical treatment - more than half at hospital.
Queen St was wrested back from mob rule at 10pm when police numbers swelled to 260.
The insurance bill for property damaged or stolen was $2.8 million. About 120 people were arrested. Most people who witnessed the night's violent scenes wondered how such a thing could happen. The committee of inquiry promptly set up by the Government led by David Lange reflected concern over how the public square could become a venue for 10,000 people, given its closeness to six hotels and the fact that people would drink from glass bottles.
The result was that local bodies were given the power to seal off public access areas and to ban alcohol at 24 hours' notice, instead of the previous 21 days.
Police waged a campaign against underage drinking and addressed their problem on the riot night of not having enough protective equipment and too few long batons.
Police also charged Dave Dobbyn, who was the lead singer of DD Smash, the band performing on stage when the concert was stopped, with inciting the violence.
But he was acquitted by Judge Mick Brown of behaving in an offensive manner likely under the circumstances to cause violence against persons or property to start or continue during the concert.
In his decision, the judge said a small element in the crowd was intent on making trouble and not interested in the music. Cans and bottles were thrown before and after DD Smash went on stage.
In a transcript made during the band's performance Dobbyn said: "I wish those riot guys would stop ..."
It drew the the crowd's attention to the presence of the riot police and cans and bottles were thrown at them but this was not an isolated event and it had been going on well before DD Smash arrived.
Yesterday, Dobbyn's manager said he was unavailable for an interview.
However, he said earlier on Maori Television: "At that time I mentioned to the crowd that the police were attacking them from behind."
In an interview with Canvas deputy editor Greg Dixon a year ago, the singer recalled: "We were right in it. There were bottles flying over us and the crowd was charging. I remember we ran for the van. The floor of the van was covered in glass. The road was completely covered in glass. I can't remember who drove but we had to get out of there real quick. It just went nuts. It turned into this beast.
"The worst thing was to stop the music. But then maybe if it didn't stop, more people would have got hurt unaware that they were being clubbed from behind.
"There was no security, it was a Friday, everyone was drinking in public out of Blenheimer bladders.
"I've often looked back at it. The judge gave me a good tongue-lashing, saying I should think about what I say next time."
Concert promoter Hugh Lynn, who was working on behalf of the sponsoring 89FM radio station, yesterday said a group with a gang connection had kicked the switch for the sound system power supply and the audience started to climb up on to the roof of the Post Office.
"When the inspector came up on stage and said 'stop the show' I said to him 'that's the worst thing you can do.'
"If the music had kept going it would have kept the attention of the people but when it stopped they turned to another show - the riot that was building."
Maori warden Hine Grindlay, now aged 70, received a Queen's Service Medal for her bravery and the Auckland City Council Good Citizen award for holding hands with others to form a human chain across the road, in front of a line of outnumbered police at the Civic Theatre.
This impromptu peace march of strangers amid the turmoil of the riot, tried to disperse people but the crowd went down Queen St and started looting, smashing everything.
Exhausted, she was handed a cup of tea and sipped it in a police car.
"Four cars were tipped over by the people that were there," she said on Maori Television.
"At the time I was not scared. You got no time to be scared. But they were issuing the guns out right and centre [because of the looting], I've forgotten about my cup of tea then. This is something else."
