Italians Paolini and Errani speed into Olympic doubles final
The straight-sets victory offered some comfort for world number five Paolini after she was knocked out in the third round of the singles by unseeded Slovakian Anna Karolina Schmiedlova.
Five-time Grand Slam women's doubles champion Errani caught Muchova by surprise with an under-arm serve on match point as the Italians clinched victory in just over an hour.
Paolini and Errani, who lost in the French Open final at the same venue in June, will face the winner of the other semi between Spain's Cristina Bucsa and Sara Sorribes and Russians Mirra Andreeva and Diana Shnaider, who are competing as neutral athletes.
Another Italian, Lorenzo Musetti, faces world number two Novak Djokovic in the men's singles semi-finals later on Friday.