The world number one was broken in the opening game of the match but went on to win the next twelve games to win the match 6-1, 6-0.
The 22-year-old Swiatek won in just 68 minutes, and she will now face Brazilian Beatriz Haddad Maia, the 11th seed, in the round of eight.
Haddad Maia defeated Greek Maria Sakkari, the fifth seed, 6-4 6-4.
Ons Jabeur of Tunisia made progress as well, winning in straight sets against Latvia’s ninth-seeded Jelena Ostapenko.
Jabeur, who is ranked eighth in Madrid, got off to the ideal start when she broke in the opening match.
The 2023 Wimbledon champion, who defeated world number three Coco Gauff in three intensely contested sets, will face American Madison Keys in the round of eight.
The 18th-ranked Keys overcame a 5-2 deficit in the opening set by breaking twice and forcing a tie-break, which she won 7–4.
