At the movie musical's New York City premiere on Monday, Oct. 6, Tonatiuh, 30, tells PEOPLE that working with Lopez, 56, is "like watching lightning strike."

"Powerful and beautiful and you're just left in awe," the actor says of Lopez, who graces the screen in the new movie as a fictional actress named Ingrid Luna.

Kiss of the Spider Woman is an adaptation of the 1993 Broadway musical of the same name, which Tonatiuh tells PEOPLE he was a "huge fan of." He and Lopez costar with Diego Luna in the new movie, which is finally hitting theaters Friday, Oct. 10, more than nine months after the movie made its world premiere at the Sundance Film Festival in Park City, Utah, back in January.

"Valentín (Diego Luna), a political prisoner, shares a cell with Molina (Tonatiuh), a window dresser convicted of public indecency," reads an official synopsis for the movie. "The two form an unlikely bond as Molina recounts the plot of a Hollywood musical starring his favorite silver screen diva, Ingrid Luna (Lopez)."

In order to portray a prisoner in the new movie, Tonatiuh also reveals to PEOPLE that he "lost 45 pounds in about 50 days."

"And I got to play two characters," he continues. "I also got to play a very classic Hollywood star," adding that the role is "a dream come true." "So for me, the challenge was exciting. It was exciting to be able to tell that very dynamic story."

Never miss a story -- sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human interest stories.

When Tonatiuh took the stage at N.Y.C.'s The Shed to introduce the movie later on, the actor compared working with Lopez and Luna, 45, to joining Earth's mightiest heroes. "It is my absolute pleasure to be here tonight, and this has felt like a moment of a lifetime, a part of a lifetime, and to be sharing the stage with the incredible Jennifer Lopez and Diego Luna was like being recruited for the Avengers," he said.