The Australian tennis No.1 was preparing to play his third round match in the Madrid Open when the lights went out across the Iberian peninsula.
After a delay of more than four hours all play was cancelled for the day.
De Minaur was due to play Canada's Denis Shapovalov in the final match of the night session on Arantxa Sanchez Vicario court, which had just hosted Coco Gauff's 6-4 6-2 win over Belinda Bencic when the outage occurred.
Gauff posted an Instagram story showing only an emergency light working in an otherwise dark locker room.
"No power where the showers are. So I'm about to take a shower and I'll let you all know how it goes," the American said.
She then discovered the water was off too. "I just had to take baby wipes and wipe myself, and spray some perfume and call it a day," she added.
Gauff also posted a photo of candles being distributed.
"I don't think we're even going to be able to go back to the hotel because the traffic lights are out," Gauff said. "It's just crazy how much we depend on electricity. It's really insane and puts it in perspective."
Having saved a match point at 5-2 down Briton Jacob Fearnley was serving to stay in the game at 6-4 5-4 against Grigor Dimitrov on the main Manolo Santana court when play was suspended.
The ATP Tour said that two singles matches and one doubles match were underway when power went out at 1234 pm local time on Monday (2024 AEST).
"The cut is preventing the use of electronic line calling systems and also left a spider cam dangling over the court inside Manolo Santana Stadium," the ATP added.
It later issued a statement saying play had been postponed "for reasons beyond the control of the organisation and in order to guarantee general safety".
Matteo Arnaldi's match with Damir Dzumhur had continued after a small break with manual line calling. Arnaldi, then 3-2 up in the second set, went on to win 6-3, 6-4.
In one of the few matches finished before the power cut Aussie doubles duo John Peers and Matt Ebden lost 6-4 7-6 (7-5) to Americans Chris Harrison and Evan King.
With AP
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