Two-time champion Maria Sharapova could face Serena Williams in the French Open last 16 after beating sixth seed Karolina Pliskova in Paris.
Russian 28th seed Sharapova produced a superior baseline game to win 6-2 6-1 against the Czech, who reached the semi-finals at Roland Garros last year.
Williams, winner of 23 Grand Slams, faces German Julia Goerges on Saturday.
The American is playing her first Grand Slam since taking a break last year to give birth to her first child.
Sharapova, 31, is competing at Roland Garros for the first time since 2015, having been refused a wildcard entry in 2017 after serving a doping ban.
She said: “This was my match to win. I wanted to perform well and give myself a chance.”