The world number one, aiming to become the first woman to successfully defend the trophy at Roland Garros since Justine Henin in 2007, won 6-0, 6-0 in just 51 minutes on Court Philippe Chatrier.
"It was a really solid performance from me. It's not easy to stay disciplined and keep your focus," said Polish star Swiatek.
"I took care of everything and I'm pretty happy with my performance."
Swiatek, who also won the title in 2020 and is targeting a fourth Grand Slam triumph, will face either 2019 US Open champion Bianca Andreescu or Ukraine's Lesia Tsurenko on Monday for a quarter-final berth.
Her path to the final was made easier earlier Saturday by the withdrawal of Wimbledon champion Elena Rybakina, a possible last-four opponent, due to illness.
That news did not put the 22-year-old off her stride, as she smashed 21 winners past her bewildered 80th-ranked opponent.
Swiatek has now secured bagels in four of the six sets she has played in the tournament so far.
