That is high praise considering Pacino has worked with some of the greatest directors of all time, including Francis Ford Coppola, Oliver Stone and Steven Soderbergh.
Pacino told Us Weekly Thursday while promoting his movie The Humbling at New York City's 21 Club that the news of Nichols' death came as a shock.
"Oh, man. It just knocked me out," said Pacino. "I'm not over the shock yet. Not that I ever will be. The shock of it is so much, it's hard to talk about it right now. It's hard to believe."
The Godfather actor worked with Nichols in 2003 on the HBO miniseries Angels in America. Both the actor and the EGOT-winning director won Emmys for the project. Pacino won for Outstanding Lead Actor in a Miniseries or Movie, and Nichols won for Outstanding Directing for a Miniseries, Movie, or a Dramatic Special.
— Hollywood Reporter (@THR) November 21, 2014
The 74-year-old actor praised the legendary director, calling him the "greatest director."
"I loved him so," Pacino told Us. "He was my friend, and he was the greatest director I ever worked with. He was."
"I loved Mike. I worked with him, and he was a friend," he said.
Director Barry Levinson, who directed Pacino in The Humbling and was with Pacino at the luncheon, concurred.
"His work is exceptional, and he's one of those guys that has an impact as a director in this business," said Levinson. "He was a man that could handle comedy and drama in an effortless fashion, and he took some risks."