The blackout occurred during the third and final act of the production on Wednesday evening, prompting the evacuation of 2,000 people from the theatre complex.
SA Power Networks said crews called out to investigate the blackout found a rat had crawled into equipment, causing a fuse to blow.
The power was restored within two hours, but not soon enough for some theatre-goers who have demanded a refund.
Organisers of the Adelaide Festival Centre said all patrons were safely evacuated.
In a message posted on Twitter, the centre said it was disappointed at the interruption and impact on the experience of audience members.
Adelaide Festival Centre’s Director of Programming, Liz Hawkins, said full refunds will be offered to patrons.
She told The Advertiser that affected patrons would also receive access to an online recording of the production.
