Sylvester Stallone opened up about a little-known story regarding his time filming Rocky IV, saying the experience almost killed him.

The actor recently posted The Making of Rocky vs. Drago by Sylvester Stallone to his YouTube, where the 75-year-old said actor Dolph Lundgren, who played nemesis Ivan Drago, went off script and nearly beat him to death.

“I got really injured during the fight,” he said of the movie’s nail-biting moment. “I had to be flown into intensive care to California from Canada.”

The Expendables star admitted that, before filming, he encouraged Lundgren to go all out and show his “dominance.”

“Well, he pulverized me,” Stallone deadpanned, noting the actor punched him right in the chest.  He didn’t know how badly he was injured until after the cameras stopped rolling.

“I didn’t feel it in the moment but, later that night, my heart started to swell, My blood pressure went up to 260 and I was going to be talking to angels,” the Oscar nominee recalled. “Next thing I know I’m on this emergency, low-altitude flight. I’m in intensive care surrounded by nuns.”

Stallone said his hospital stay lasted four days and, once he was discharged, he “had to go back and finish the fight.”

He said he was upset by the movie’s final cut because that punch that sent him to the hospital was left on the cutting room floor.

“How could you take that out?!,” Stallone quipped.

Rocky IV premiered in theaters in 1985 and earned $300 million during its box office run.