The 23-time grand slam singles champion had four match points but Pliskova won six straight games to claim a 6-4 4-6 7-5 victory and set up a last-four clash with Naomi Osaka.
Novak Djokovic had an easier-than-anticipated evening when Kei Nishikori pulled the plug with a thigh problem trailing 6-1 4-1. He next faces Frenchman Lucas Pouille, who upset Milos Raonic to make his first slam semi-final.
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Fair dinkum mate
The truncated nature of Djokovic's match led to an extended on-court interview with Jim Courier, during which the world number one decided to test out his Australian accent. He may wish to let his racket do the talking in future.
It is not every day your wife defeats Serena Williams from 5-1 and match points down, and Michal Hrdlicka did not hold back in his celebrations.
Who's up next?
A bumper day of action at Melbourne Park on Thursday features both women's semi-finals and the men's clash between Rafael Nadal and Stefanos Tsitsipas.
Tsitsipas will look to build further on his landmark win over Roger Federer by becoming only the third player after Juan Martin del Potro and Djokovic to defeat him and Nadal at the same slam.
The first women's semi-final will see eighth seed Petra Kvitova take on surprise package Danielle Collins before Pliskova meets Osaka.