The new Kendrick Lamar blasts from an old sound system: "My left stroke just went viral. Right stroke put lil' baby in a spiral."
Eight young men wearing singlets and track pants and baseball caps skip to the beat.
Behind them hang black punching bags and speed balls. In front, the words "perfect practice makes perfect" are scrawled on stone above a mirror that almost spans the length of the wall.
There are other slogans pinned up or written down around the gym. 'The pain will go away but giving up will stay forever."
It's 6pm and the light coming in through a few dirty windows is fading. Everyone is glistening.
Barely an inch of the place isn't covered by black-and-white photos and polaroids and posters: Ali v Liston, Tua v Cameron, Parker v Ruiz.
Boxing gyms honour their heroes, and this one, on the Papatoetoe section of Great South Road, used to be WBO heavyweight champion Joseph Parker's second home. The biggest hero of them all.
Mose Auimatagi jnr has got his own belt. It rests on the mantelpiece in his living room.
The 21-year-old is New Zealand's middleweight champion. He's rated by respected website Boxrec as the country's third best pound-for-pound fighter and is the youngest in the top 50. His nickname is 'Iron Mose' and trainer Grant Arkell says he's got a big right hand and a big left.
"Big future, that boy."
He also works 40 hours a week at Fisher & Paykel.
"Got to pay the bills somehow," he says.
Boxing has a reputation for producing loudmouth egos. Mose destroys that mould.
"[Being middleweight champ] is not too bad. I've still a long way to go. My parents are prouder than me. I'm not too fussed."
He's been coming to the gym for a third of his life.
"Seven years on Friday," he proudly states. "Coming here was the best day of my life."
He's wanted to box since he was four and saw the trophies won by his uncles at their house.
"I always wanted my own trophy. The dream started then."
His dream is to be world champion. That's what keeps him coming back. He is coy about his current title because he has bigger ambitions. For a while, his mum kept him from fighting.
"Mums being mums, they don't want to see their sons getting hurt."
Fighting is everything. The gym is everything.
"It's competitive here but it's never hurtful or prideful. This is my first and last gym."
Mose's "money punch" is a vicious gut shot. He's the first to admit he got it from Tino Honey, an older fighter who has been training in Papatoetoe for 13 years. He finally went pro two years ago.
"Tino taught me a lot of things. A few years ago, he got me with a body shot in sparring and later he told me how to do it," he says.
Both have a Samoan background.
"Tino was a big inspiration for me."
Tino Honey ("yes, that is my real name") lost his first six amateur fights.
"I finally won one and that for me is something I'll never forget."
Pound-for-pound, the 25-year-old is ranked 50th in New Zealand by Boxrec. He tries not to tell people he's a boxer.
"I find that boxing is something that's just for me. I don't want to be big-headed and go around telling people I fight."
That doesn't mean he keeps to himself. He's the first to give young fighters advice. He describes the gym as a brotherhood and a family.
Tino's dad used to box.
"Obviously, as a young kid, you want to be like your father."
He smiles, describing himself as a "hyper kid" growing up.
"It was tough coming here at first - fighting older boys and finding the motivation to train hard - but it was good," he says.
Boxing gave him discipline and the confidence to talk to people.
"A lot of kids have bad backgrounds and coming to the gym changes that. It's a lot to motivate yourself to come every day, but for me, it changed my energy into something positive."
There's an old photo of him from more than a decade ago on the wall. It's one of the first things you see when you enter the gym. He's a child and has just won a fight and his smile seems as wide as the frame. As an amateur, he fought 85 times. And yet, "no one gets used to getting hit".
Boxing is Grant Arkell's life. A collapsed lung put an end to his fighting ambitions. He tried to set up a gym but it failed financially. His second attempt, 26 years ago, was the Papatoetoe Boxing Club.
He takes boxers from 14 up.
"I don't like the young ones boxing - their concentration isn't the best."
That hasn't always been the case. He used to take 10-year-olds - such as Joseph Parker - but most, including Tino Honey, have since told him they wish they hadn't started so young.
"They feel like they lost their childhood."
He has trained fathers, sons, daughters and brothers. He has trained Samoans, Tongans, Indians and Iraqis.
"Some come here for fitness, others are sent by their parents if they're naughty and not good at school."
The sport is a pure thing. Yet, the money and the suits are a necessary evil.
"The corporate types come in and do three months' training, have one fight, then disappear. It's not only businessmen, but ex-footballers and other sports people who want to have a go, but it doesn't do boxing any justice.
"Some of the corporates that turned me down when Joseph was a lot younger now back him. It's only once they see they can make some money they jump on board."
The gym is run on a shoestring. It relies on financial support from the pokies. It also has a waiting list of almost 100 but Arkell says calling it the "Joe Parker effect" is too simple.
"We've always had a waiting list here, we just can't fit everyone in. I could be here all day and every day but it's a matter of finance."
There are eight gyms within 6 km and they're all busy. There's one six doors down.
Fighters at Arkell's gym have to pay $10 per week. The ones who have jobs pay $12.50.
"A lot of the younger ones don't have the $10 but I still let them train."
Taking new equipment, travel, accommodation and food into account, he needs about $70,000 a year "to make this place run properly".
"There's also the parents who don't have a lot of money, but I don't want to leave them behind when we travel . . . so that support we get from the pokies is vital."
He gets perks in other ways.
"When the young ones go to competitions and try their hardest, win or lose, and you see the improvement, that's your payback."
He stays in touch with many of those too old now to fight. One or two of his former protégés have opened their own gyms. Some are trainers elsewhere.
"They sometimes come around my home to see if I'm all right."
hen Joseph Parker was a boy, he was taunted and followed home by a few rivals one day after school.
When he reached the sanctuary of his Mangere house, his dad kept him from going inside and asked his son's rivals, "which one of you wants to fight my son?"
A big lad put up his hand and gave Joe a bit of a beating. His dad intervened before things got out of hand.
"Did I do good, dad?" Parker asked.
"You did good, son. I'm proud of you. But I never want to see you fighting outside a ring again. If you want to fight, you have to do it properly."
It's a tale Parker's parents told his biographer, David Riley, and one Grant Arkell says shows the early makings of the man.
Parker is the Papatoetoe gym's biggest success story. But at first, the fighter was just big.
"He was 10 when his father brought him here and he was just a little, overweight boy who wasn't really interested," recalls Arkell.
"He told me he'd rather be playing volleyball, but his dad told him to keep coming back."
Arkell remembers Parker's brother John being the better athlete.
"He could do 1000 sit-ups and had a six pack when he was 10.
"Joseph was happy doing a little bit of training here and there and talking to the boys, but when he had success overseas, he realised he had some talent."
Parker had a top amateur career.
"He's the only New Zealand boxer to beat a Cuban . . . Tua or Cameron never beat a Cuban," Arkell says.
He turned pro at 20 under the guidance of Sir Bob Jones, a decision Arkell still disagrees with.
"I found out about it when I read the paper - I didn't even know. Bob rang me up and I told him he was a fool because Joe wasn't ready and still had a lot to achieve in the
amateurs," he says.
"I really wanted him to go on to the Rio Olympics, but he made the decision and no hard feelings."
Parker came back to Papatoetoe before his last fight. "He trained here for a couple of nights and gave the guys some advice. They spent a lot of the time taking photos," Arkell laughs.
Parker's success can only be good for the sport but Arkell says boxing has always been popular in Papatoetoe.
"When Joe fights, you do get a lot of guys coming in wanting to join. It was the same when Cameron and Tua were fighting, but there's a steady trickle of people coming all the time."
Arkell speaks about boxing with a pensive mix of wistful nostalgia and ardor. But the future of the sport isn't clear.
"There are other [New Zealand talents] as well as Joe, but only one in a few get through. It's not like rugby. Often the money's just not there."
He beams when talking about Auimatagi jnr.
"Mose is going really well - I took him to Australia last year and he knocked their golden boy out in one-and-a-half minutes," he says.
"He's had a lot of offers of fights from overseas, but I'm just taking him quietly. He's in the hardest division around. He's got a long way to go before he can get to where Joseph is."
When he had success overseas, he realised he had some talent.
Parker was threatening greatness when Auimatagi jnr joined the gym.
"If he can do it, I can do it too," he says. "It is tough, but if you want to be a champion and get out of the place you don't want to be - if you want to be better than your opponents, or the situation you're in, you've got to work. You've got to train."
Most of the fighters who were skipping have moved on to bag work.
Arkell stands beside one as he unleashes a combo on the leather.
A kid with big arms is on the weights. Tane Tautalanoa has just turned 17 but has already had 34 amateur bouts and represented Tonga at the junior world champs.
Both he and Arkell want his flag to switch to New Zealand - where he was born. "I want to put my family name out there."
Bravely, 19, and Zalmon, 17, are sparring in the ring. A couple of parents watch from some peeling armchairs. The brothers are going to Samoa soon to try out for the
Nearby, a woman takes photos and chats with one of the fighters.
Karen Otai works full-time at Adidas, but in the evening voluntarily runs the gym's social media accounts and clothing range.
"I'm just a local who is passionate about the gym. The thing I love about boxing is you may be in the ring by yourself - but it's a team sport before you get there," she says.
Otai keeps coming back because she wants to help change the perception of boxing.
"It's not just for trouble-makers and bad boys. Especially out south, many of these guys come from rough backgrounds and put in so much dedication and discipline to come to one place every night and train for three hours."
She goes back to taking photos. It's still hour one of a three-hour session.
Tino shares a joke with Tane. Grant Arkell's grandchildren run among them playing tag. Mose is still shadow boxing by the mirror.
Painted on the glass is "2018 Commonwealth Games, Australia."
The new Kendrick Lamar is coming to an end: "Hol' up. Sit down. Be humble."