It is the stuff of an understudy’s nightmares: waiting in the wings as a baying audience demands their money back because the show’s Hollywood star cannot perform.

But Ria Jones was left triumphant as she stepped in to Glenn Close’s Sunset Boulevard shoes, after waiting 25 years to play the role in the spotlight.

Jones, a Welsh singer, faced furious boos and walk-outs after it was announced Close was unwell, with audience members paying up to £150 to see the American actress left disappointed.

By the end of the night, she received what one audience member described as one of the longest standing ovations she had ever seen on the London stages.