A skinny 19-year-old AJ made his debut representing Finchley Amateur Boxing Club at the Boston Arms pub on November 27, 2008.
Joshua took to boxing relatively late, hence why he only had his first bout in his late teens.
However, he quickly became very adept in the sport and went on to cap his amateur career by winning an Olympic gold medal at London 2012, before becoming a two-time unified world champion as a professional.
Back in 2008 though, AJ was a far cry from this elite heavyweight.
His opponent in his debut was Nathan Brede – another teenager who was also competing in his first ever fight on that date.
“I remember seeing him,” Brede told the Independent several years later, “He was this great big lump, but I still wanted to take the fight.”
“I had travelled there so I didn’t want to go home without boxing. I think he outweighed me by about 8kg.
“He was huge but honestly I wasn’t fazed one bit by the idea of getting in there with him. Obviously, it’s just a fight at the end of the day.
“I’m only 5ft 10in, he’s 6ft 6in and he was tall and ripped. Because of that, they weren’t sure but I insisted I wanted to do it.
“I remember thinking, ‘If we were outside on the street and he wanted to fight, I wouldn’t have run away, so why would I go home without fighting now?'”
The teenagers even had a conversation before their fight.
Brede explained: “I remember he asked me what bout I was in. He obviously didn’t realise I was fighting him because I was so much smaller.
“When I told him I was bout nine he realised we were fighting. He obviously took a bit of confidence from the size difference and I don’t blame him.
“And this is how bad it was for me, I remember my coaches actually told me that Joshua was a southpaw.
“So when we were warming up on the pads, we were preparing for a southpaw. Then when he comes out he was orthodox. I just thought, ‘Oh great.’”
The fight was over relatively quickly as Joshua knocked Brede down with a strong jab inside the first 20 seconds.
Brede made it back to his feet but was soon down again just ten seconds later, prompting the referee stopped the contest after around half a minute.
While many would have been thankful that they only had to spend 30 seconds in the ring with AJ, Brede was furious that the fight ended so soon.
“I remember getting up from the first one and I wasn’t hurt one bit,” Brede explained, “The ref gave me an eight count and let us carry on.
“We went into a clinch and just the sheer weight pushing down on me sent me down again, he didn’t hit me with any punches.
“Then the referee waved it off, I was gutted. I didn’t even wait for the result I just got straight out of the ring.
“I was absolutely steaming with the stoppage. I wasn’t happy at all.”
As time has passed and AJ has created a legacy as a British heavyweight great, hopefully Brede has been able to come to terms with the defeat.