A teenage knifeman was wrestled to the ground by furious bystanders moments after he stabbed a 22-year-old student to death in a botched robbery yesterday.

Electronics student Saishwar Krishna Naidu died after being repeatedly stabbed in the abdomen while trying to prevent a youth robbing his family's Finlayson Superette in Clendon about 1.30pm.

Football fan Mr Naidu died as ambulance crews battled to save him as his distraught family looked on. He had been working part time at the superette owned by his father.

Police said members of the public chased and caught the alleged offender after the stabbing.

Witnesses told how Mr Naidu's assailant had stood in the door of the dairy after the attack "huffing and puffing".

Stacey Ngatuere, 26, said she saw two men tackle the offender to the ground. "They nailed him in the middle of the road and were trying to restrain him," Ms Ngatuere said.

"He was putting up a fight and they were hitting him everywhere - they were all in."

The offender was left huddled in a ball groaning on the road.

"He had blood on his face and his eye looked puffy," she said.

At first Ms Ngatuere thought she was witnessing an assault and called for the attack to stop. "They told me to call the police because he had just stabbed the shopkeeper."

Police later asked her where the knife was and bystanders told her it was still in the shop. Mr Naidu was humble and always smiled, she said.

"He kept to himself, was well-presented and polite."

Another neighbour, Grant Hills, was cleaning his car when he heard what sounded like a brawl outside.

"It was a couple of local guys, Maori, in their 20s. They said he'd stabbed someone."

Mr Hills heard screaming coming from the shops.

"The boy's family was there. I think they were trying to get in the back of the ambulance."

The screams got louder once they were told he had died.

"They were huddled together on the side of the road ... It's so sad."

He said Mr Naidu was "a nice boy who never said much. We just made small talk".

Neighbours told the Weekend Herald they saw a bloody sweatshirt being taken from the shop.

Last night family were gathering at his parents' Manukau Heights home. An aunt said the family were too distraught to speak. "The mum isn't doing very well," she said.

A family spokesman, Narendra Gounder, said he was a dearly loved son. "You couldn't have asked for a better son than that."

Police said the youth in custody was expected to face "serious charges" over the incident.

Former school mates of Mr Naidu from Manurewa High arrived at the scene last night after getting texts about what had happened.

The 15-year-old daughter of a woman who was working in the superette at the time of the killing ran over after she heard screaming.

"I was trying to help my mum. She told me to look after [the victim]. Everything in the shop was scattered everywhere ... and there was blood. [The victim] was curled up on a chair. Mum was really freaked out."

She said her mother had worked there for six or seven years.

One former friend, who didn't want to be named, said, "Krishna played a lot of Xbox and PS2. He was nice and gentle. He wouldn't have hurt a fly."

They thought he'd worked at the superette since his father opened it.

A close family member, who also didn't want to be named, described Mr Naidu as "very humble, disciplined and respectful". The 22-year-old was a student at Manukau Institute of Technology, studying electronics.

"The superette was run by the family so all the family members took time off to look after the shop. [The victim] used to help them out during the weekends and holidays," the family member added.

He said Mr Naidu was born in Fiji but came to New Zealand about six or seven years ago. "His parents are really broken down. He was murdered and his sister lives in Australia.

"We were very close and he was a very good friend of our son's."

He said the family had one year left on the lease of the superette. He said Mr Naidu liked movies and spent his spare time at home studying or in the superette.

A friend of the family described Mr Naidu as a good child. "He came from a highly respected family. He had his own goals and aspirations and look what's happened to him.

A month of mayhem

* January 1: Eleven-week-old Tahani Mahomed dies of head injuries.

* January 7: Michael Hutchings, 18, is found dead in the Clutha River.

* January 8: Bronwyn Whakaneke, 33, is found dead in Waitangirua.

* January 9: Dunedin student Sophie Elliott, 22, is stabbed to death.

* January 17: Scottish tourist Karen Aim, 26, is killed in Taupo.

* January 20 : An unidentified woman aged between 30 and 50 is found dead in the Wairoa River.

* January 21: Chattrice Maihi-Carroll-Poipoi, 46, is found dead in her Napier home with stab wounds.

* January 25: Saishwar Krishna Naidu, 22, stabbed to death in parents' dairy.

* January 26: A man is found dying in a Tokoroa street.

 -NZ Herald