World number two Gauff brushed Russian 20th seed Ekaterina Alexandrova aside 6-0, 7-5 to step up her pursuit of a first Roland Garros crown, and second Grand Slam title.

"It was tough. The whole match I think I played well to be honest," said Gauff, a losing finalist in Paris in 2022.

Former US Open champion Gauff will play reigning Australian Open champion Madison Keys or unseeded Hailey Baptiste in an all-American quarter-final.

Sixth seed Andreeva also moved through in straight sets as she cut short an attempted fightback by hitting partner and ex-compatriot Daria Kasatkina to advance 6-3, 7-5.

Kasatkina, ranked 17, is now playing for Australia after switching allegiance from her native Russia.

"It was a hell of a match," said Andreeva.

"Honestly I'm so so happy I won, I hate playing against her, we practise a lot and even practice is a torture for me."

She is through to her second major quarter-final, having reached the last four at Roland Garros 12 months ago when she knocked out Aryna Sabalenka.

The 18-year-old Andreeva is the youngest woman to reach back-to-back Roland Garros quarter-finals since Martina Hingis in 1997-98.

She next plays either third-ranked American Jessica Pegula or France's last remaining player in Paris, Lois Boisson.

France's 361st-ranked Lois Boisson shocked US third seed Jessica Pegula in three sets to reach the French Open quarter-finals on Monday.

The 22-year-old wildcard recipient won 3-6, 6-4, 6-4 and next meets Russian sixth seed Mirra Andreeva for a place in the semi-finals.

She becomes the first French player to reach the last eight of their home Grand Slam since 2017, and first as a wildcard since Mary Pierce in 2002.