John G. Avildsen, Director of 'Rocky,' 'The Karate Kid,' Dies at Age 81

John G. Avildsen, a longtime film director who won an Academy Award for his work on the boxing classic Rocky, died Friday. He was 81.

Jake Coyle and Anthony McCartney of the Associated Press reported the director's son, Anthony Avildsen, confirmed his father's death was due to pancreatic cancer.

Avildsen also directed The Karate Kid, a cult classic with a similar underdog storyline as Rocky, and the bull-riding movie 8 Seconds.

Sylvester Stallone, who earned his breakthrough playing the role of Rocky Balboa, praised the Oak Park, Illinois, native in a statement released Friday night, according to the AP.

"I owe just about everything to John Avildsen. His directing, his passion, his toughness and his heart—a great heart—is what made Rocky the film it became," Stallone said. "He changed my life, and I will be forever indebted to him. Nobody could have done it better than my friend John Avildsen. I will miss him."

His impact went far beyond the sports genre, with hits such as Joe and Save the Tiger.

Avildsen's ability to strike the right notes with rags-to-riches stories brought him his greatest critical successes. Along with the Academy Award for Rocky in 1977, he also won a Blue Ribbon Award and a Directors Guild of America Award for the film.

His career will be remembered in the documentary John G. Avildsen: King of the Underdogs. The project's official Facebook page announced June 2 it will be released Aug. 1.