The curtain failed to rise on the premiere of a play starring Hollywood actress Alicia Witt.
Theatregoers who had paid between £13 and £22 were turned away from the opening night of American thriller The Shape Of Things because of an electrical fault.
A problem in the lighting box controlling special effects at the Theatre Royal, Brighton, forced last night's show to be cancelled.
It is the first time in more than 25 years a play has been abandoned at the theatre with the audience already in their seats.
People who had paid to see the performance have been offered refunds or tickets for alternative nights.
Theatregoers were waiting for the curtain to rise when theatre manager Dan Prattley appeared on stage and said there would be a 15-minute delay.
He advised people to use the bar and reappeared a few minutes later to say the problem was still being tackled.
However, at 8.20pm theatre chief-executive Julien Boast appeared and announced the play was being called off.
He said: "I am sorry, the cast and the crew are sorry, but we cannot go on with the show due to technical problems with the lighting."
Mike Howard, theatre critic for The Argus, said: "A lot of people were really disappointed.
"Although people were offered their money back, many had come a long way to see the first night."
Christine Webber, from Rottingdean, said: "The theatre did its best.
"The audience was really sympathetic. We met people and went to the bar and then had another drink in the Colonnade bar next door."
Theatre Royal spokesman Tim Sitwell said: "We could not get power to the main lighting box.
"As this is a fairly technical play, we could not have gone ahead without the proper effects. It would have been like a play reading."
It is the second time in the past month there has been an electrical problem at the theatre.
A concert by Lulu started late and had to be cut short because of the technical difficulties.
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