After the greatest championship heavyweight fight in modern-day boxing, a rematch was on the table. However, Wladimir Klitschko surprisingly retired from the sport, turning down a massive pay day in the process.
And he's finally explained his decision behind calling it day.
Joshua fought Klitschko in what was billed as his toughest test to date. The Ukrainian boxer was a wounded animal following his decision loss to Tyson Fury, and looking to regain his world titles.
The pair of fighters produced an instant classic. Joshua floored Klitschko, before hitting the canvas himself.
The Watford-fighter eventually recorded a stunning 11th round stoppage.
Joshua and Klitschko embrace. Image: PA
A rematch was written in the contract, and in the works following their firefight at Wembley Stadium.
But Klitschko opted out by retiring from boxing.
On BBC's documentary profiling their epic world title bout, Joshua asked Klitschko why he retired.
"This is the first time we've met since our fight, and I have to say, it's an honour to be here a year on," Joshua said.
The undefeated Brit added: "It takes two to tango and Wladimir was a great dancing partner that night, when I proved I have the heart and ability to compete at world level. It was the closest I'd ever come to losing. It was just a classic heavyweight fight."
Klitschko replied, saying: "The way I boxed, was the way I acted my life. I have to make sure everything sits.
"And I knew my stocks went up after I lost for some weird reason, but it was the most complicated and difficult decision of my life ever.
"For 27 years I've been doing it and then when you know you gotta pull the plug that's it, it's done.
"So I was saying to myself 'Wlad c'mon man you gotta make a decision', because one day I'd wake up and say yes I'm gonna go for it, then second day I'd wake up and say wait a second it's about AJ, it's about rematch.
"So you have to be honest with yourself what is your gut feeling saying because as soon as your brain turns on, you're gone."
Despite a multi-million - eight figure - deal reportedly being offered, Klitschko called time on his illustrious career, retiring with a 64-5 professional record.