Mailata also fought Parker at the 2012 New Zealand Olympic trials but was reluctant to make a prediction ahead of the Cardiff showdown.
"It was a nerve-wracking experience but one that also allowed me to grow because I was very young. At the time, Joe was a role model of mine, so fighting him at that age, it did nothing but prepare me for what was ahead.
"Both fighters have similar attributes, it just comes down to who uses them best. They're both fast and have good footwork. Anything can happen in the heavyweights."
Mailata, who competes in the 91kg-plus division and expects to weigh in around 125kg, comes from a family of fighters but his boxing pathway was secured only after a knee injury curtailed his promising league career.
He first joined a gym in Mangere, and remembers seeing Parker in the papers and deciding to be dedicated to the sweet science. He is passionate about the sport; inspired by the individual challenge of making it on his own. Outside the ring, it also keeps him honest in life.
As a wide-eyed 18-year-old, Mailata lost to eventual silver medallist Joseph Goodall in his first fight at the Glasgow Commonwealth Games in 2014. Four years on, and having dropped 5kg in his recent trip to the UK, he feels much more confident of his medal chances.
"I didn't really take hold of what it meant at that time. Physically, I was prepared, but mentally, I wasn't all for it. This time, it's different. I definitely know my reasons for being here, going to the Games and what I want to achieve."
Surviving as an amateur boxer in New Zealand is difficult. After splitting from his long-time coach, Nyika ended up training in a Hamilton car park. Mailata plans to auction off gloves signed by Joshua to help fund his campaign.
Ultimately, the only way to make a living is turning pro.
"This sport, especially in New Zealand, you have big dreams and little dollars. You have got to do that for yourself. I've been lucky to have good people support me. The biggest reward is to go to the Games and bring back a medal for them.
"It would mean the world to my mum. She's had to be patient with me chasing this dream.
"For myself, it's everything. I've passed up a lot of opportunities so I can chase this dream. This is the final stride.
"My biggest goal is going pro. That's the reason why I started in the first place. I see amateurs the same as people studying before working. I can't go pro before I understand what the game is really about, so the goal is to dominate the Commonwealth and then think about the next step."