Czech snowboarder Maderova lands shock Olympic parallel giant slalom win
The 22-year-old's unexpected triumph in Livigno on Sunday ensured the gold medal heads to the Czech Republic for the third straight time after Ledecka's triumphs in 2018 and 2022.
Ledecka had appeared on course to seal a unique treble at the Milan-Cortina Games before losing narrowly at the quarter-final stage.
But Maderova stepped into the breach, romping to a comfortable victory over Ledecka's conqueror Sabine Payer by 0.83sec in the final, watched by a gaggle of her family and friends as well as Czech President Petr Pavel.
Ledecka and Maderova had finished in the top two positions in qualifying, raising hopes they would meet in an all-Czech final.
"In the qualification, I was second and Ester was first. It looks really good, because if we go every single round how we should, we can meet in the big final," said Maderova.
"But sadly, Ester didn't go to the big final. I'm sad about it, but I am so happy I can give the gold medal to Czechia."
She added: "I still can't believe it. It's unbelievable. It's crazy. I told myself 'Now or never, just go', and I did it."
Maderova, who has never topped a World Cup podium, said the president had spoken to her after her win.
"He said, 'Thanks and good job', and congratulations," she added. "It was great."