Sylvester Stallone is finally be stepping away from starring roles in some of his biggest movie franchises like The Expendables and the Rocky spinoff Creed, but when looking back on more than five decades of movies, it seems that the Oscar-winner has one moment from all of his films that stands out more than the rest.

Sharing on his Instagram account, Stallone made the surprise revelation that working on Rocky Balboa, the sixth movie in the Rocky franchise, is the highlight of his career. Considering Rocky V was not received with the same exuberance as its predecessors, Rocky Balboa’s arrival more than a decade later was a risk and a triumph that saw an underdog come through in a big way. Stallone posted a behind the scenes video, and wrote:

“I love the sixth installment. It was the toughest challenge I ever had. Took over 12 years to make happen. No one wanted to make it. Absolutely no one. It was considered a joke. But in my heart I loved the idea and thought if I’m going to go out, I want to go out making this movie. Even though no one involved with the other previous productions wanted anything to do with it, and it finally made against all odds!!! When people ask what is your most memorable film moment. Rocky Balboa, without a doubt. That was the ultimate challenge. The first Rocky of course was amazing… But this one was almost impossible dream.I pushed that boulder uphill for 12 long years against overwhelming negativity until it finally happened… Almost by accident. Someday I’ll tell the whole story. The irony is a Rocky Balboa had never been done, even though no one wanted to do it, the story of Creed would’ve never been made. My thanks to MGM. So Keep Punching!”

Related: Rocky vs. Rambo: Sylvester Stallone Details Who Would Win In a Fight

Creed Would Not Have Happened Without Rocky Balboa

Creed 2
Metro-Goldwyn-Mayer Pictures

Although there were plenty of doubts about the sixth Rocky movie when it was released, as well as proving its critics wrong, the film also instigated a revival of the Rocky franchise, leading to the release of the spin-off franchise of Creed, in which many of Rocky Balboa’s plot points were continued.

Creed centered on the illegitimate son of Rocky’s adversary and friend Apollo Creed, Adonis, played by Michael B. Jordan. The first two Creed movies were successful from both a commercial and critical point of view, proving that sometimes a story isn’t done until it’s done. Creed 3 is currently filming, with Jordan also acting as director this time around, while Stallone has ducked out this one after appearing to pass on the torch in Creed II.

Recent set photos have shown Jordan training for his role, along with co-star Jonathan Majors who is thought to be appearing as the son of Clubber Lang in the latest sequel, and additionally, Stallone has teased the possibility of a Rocky prequel TV series also being in development. It is clear that even though Stallone doesn’t seem to be appearing in any more Rocky-related movies, he is still involved in the future of the franchise.