Sir Ian McKellen, best known for his portrayal of Gandalf in "The Lord of the Rings" trilogy, was hospitalized on Monday after suffering a fall during a performance in London.

McKellen, who is fronting "Player Kings" at Noel Coward Theatre, was in the middle of a fight scene when he toppled off the stage. The rest of the performance was canceled, and the theater was evacuated.

According to a BBC journalist inside the theater, McKellen, 85, cried out in pain from the startling accident.

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Ian McKellen in a burnt orange suit smiles on stage

Sir Ian McKellen, 85, fell off the stage during a performance of "Player Kings" in London. (Isabel Infantes/PA Images via Getty Images)

On Tuesday, the Noel Coward Theatre released a statement saying the actor was in "good spirits" and expected to make a full recovery after undergoing scans.

McKellan reprised his role of Gandalf in "The Hobbit" film series, but is also well known for his roles in the "X Men" franchise, the live adaptation of "Beauty and the Beast" and playing a senior Sherlock Holmes in "Mr. Holmes."

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A sign of the "Player Kings" fronted by Ian McKellen in London

Ian McKellen stars in "Player Kings," an adaptation of Shakespeare's "Henry IV Part 1 and 2." (Aaron Chown/PA Images via Getty Images)

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"Sir Ian seemed to trip as he moved downstage to take a more active part in the scene," audience member Paul Critchley told the PA news agency of the incident. "He picked up momentum as he moved downstage, which resulted in him falling off the stage directly in front of the audience."

The theater says staff and two doctors in the audience came to the actor's assistance.

Ian McKellen as Gandalf and Elijah Wood as Frodo in "The Lord of the Rings: The Fellowship of the Ring"

Ian McKellen played Gandalf opposite Elijah Wood's Frodo in "The Lord of the Rings: The Fellowship of the Ring." (New Line/WireImage/Getty Images)

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"Player Kings" is an adaptation of Shakespeare's "Henry IV Part 1 and 2." McKellen plays the roguish John Falstaff.

The play will resume on Wednesday, with McKellen in the production, according to producers.

The Associated Press contributed to this report.