Sylvester Stallone
Sylvester Stallone is seen in this undated still from "Rocky Balboa." Getty Images/AFP

John Avildsen, who won an Academy Award in best director category for 1976 hit “Rocky,” died at Cedars-Sinai Medical Center in Los Angeles due to pancreatic cancer. He was 81.

Avilden was born in Oak Park, Illinois and was educated at the Hotchkiss School in Lakeville, Connecticut, and New York City. He worked as an advertising copywriter and then severed in the Army as a chaplain’s assistant for two years. Following this, he shifted his focus on making industrial films for companies and worked as an assistant to directors. He directed his first movie in 1969, "Turn On to Love." However, he first received critical acclaim for 1970 “Joe.”

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“Rocky” was made on a modest budget with less than $1 million. He took in then-unknown Sylvester Stallone as the lead actor. The movie was complete in 28 days and went on to become the highest-grossing movie in 1976. It generated $225 million in ticket sales.

The movie received ten Academy Award nominations, of which it won three — including Best Picture and Best Director.

Stallone expressed condolences and said he would be “forever indebted” to Avildsen.

“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.”

Directors Guild of America (DGA), which Avildsen joined in 1966, called him a “prolific director.”

“We were greatly saddened to learn of the passing of beloved director John Avildsen. His iconic Rocky, which won the DGA Feature Film Award in 1976, has been lionized throughout our culture as the quintessential underdog story – a recurring theme in his notable body of work which included Save the Tiger and The Karate Kid franchise. Throughout the decades, his rousing portrayals of victory, courage and emotion captured the hearts of generations of Americans,” DGA said in a statement.

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“A prolific director, John always found the time to give back to his Guild – from his service on our National Board as First Vice President and Assistant Treasurer, to his work on the Eastern and Western Directors Councils and DGA Negotiating Committee – advancing and protecting the creative and economic rights of directors. Our hearts go out to his family and friends during this difficult time,” it added.

A documentary based on Avildsen, “John G. Avildsen: King of the Underdogs,” was premiered earlier this year at the Santa Barbara International Film Festival. The movie is slated to release in August. It was shot by his son Anthony Avildsen.

“He was a pretty extraordinary man in my estimation. He was super talented and very driven and very stubborn and that was to his detriment but also often to his benefit,” Anthony said of his father’s death.

Avilsen’s other movies include “Cry Uncle!,” “Neighbors” “The Karate Kid,” “The Karate Kid Part II,” “The Karate Kid Part III,” “Lean on Me,” and “8 Seconds.”