The 19-year-old Pole, who dispatched the top seed Simona Halep in the last 16, was down 3-1 in the first set but she won five consecutive games to claim the opener after 43 minutes
She maintained her poise and was too powerful for the world 159 who had beaten the 20th seed Maria Sakkari in the third round and the fifth seed Elise Mertens in the last 16.
Romp
It was one-way traffic in the second as the world number 54 maintained the pressure.
"It was pretty hard for me at the beginning,” Swiatek told the on-court interviewer Marion Bartoli after the match.
“All my other matches started at 11am, so to start at 9pm … it felt like the middle of the night. I am just so happy to make it into the semis."
Swiatek, who began her tie against Trevisan after the five hour marathon between Dominic Thiem and Diego Schwartzmann, will play another qualifer - Nadia Podoroska - for a place in Saturday’s final after the 23-year-old Argentine upset the third seed Elina Svitolina in straight sets.
It was 6-2, 6-4 to the world number 151 who had never won a match on the clay courts in Paris before the 2020 tournament.
