Coco Gauff has led a parade of US women into the last-16 of the French Open -- and her teammate Jessica Pegula reckons it's about time.

Second seed Gauff, who as the 2022 runner-up at Roland Garros, is the pick of the five Americans who've battled into the fourth round, found it harder than she may have hoped to subdue Czech Marie Bouzkova 6-1 7-6 (7-3) on Saturday.

Gauff completed an excellent day for the US challenge after third seed Pegula came from a set down to knock out 2023 Wimbledon champion and 2019 Roland Garros runner-up Marketa Vondrousova 3-6 6-4 6-2.

Seventh seed Madison Keys also progressed, winning the all-American clash with Sofia Kenin 4-6 6-3 7-5, while 16th seed Amanda Anisimova had also made it on Friday by defeating Danish 22nd seed Clara Tauson 7-6 (7-4) 6-4.

That's set up Anisimova, the 23-year-old from New Jersey who was a teenage semi-finalist at Roland Garros six years ago, with a fourth-round pop at world No.1 Aryna Sabalenka, who has dropped just 10 games in three matches so far.

"We're both some pretty big hitters, so I'm sure we're going to be going at it back and forth a bit," said Anisimova.

Perhaps the surprise US fourth-rounder is world No.70 Hailey Baptiste, who had hitherto looked most uncomfortable on this surface but who surpassed herself by battling past Spaniard Jessica Bouzas Maneiro 7-6 (7-4) 6-1.

"About time," smiled Pegula about the US surge.

"It's exciting to see. Obviously, you want to see your fellow countrymen do well on the other side, and I'm always actually keeping up with them quite a lot."

She's seeking to become the first American woman since Serena Williams a decade ago to take the title, while no US man has won for 26 years since Andre Agassi.