Caroline Garcia, Kristina Mladenovic and Alize Cornet made it three-from-three for the French contingent at the Connecticut Open.
French prospects Caroline Garcia and Kristina Mladenovic both scalped seeds at the Connecticut Open on Monday, while Eugenie Bouchard's struggles continued.
Garcia coasted past sixth seed Timea Bacsinszky 6-3 6-1 in New Haven, while Mladenovic accounted for eighth seed Sara Errani 6-2 4-6 6-4 at the WTA Premier hard-court event.
Mladenovic's win left just two seeds in the top half of the draw in the second round - Lucie Safarova (four) and Karolina Pliskova (five).
Pliskova escaped with a narrow 2-6 7-6 (7-5) 6-2 victory over qualifier Polona Hercog, while Safarova dismissed Daria Gavrilova 6-3 6-4.
Seventh seed Agnieszka Radwanska thrashed Coco Vandeweghe 6-0 6-2, but the American was not the heaviest loser on Monday - that dishonour belonged to Bouchard.
The Canadian's struggles have been well-publicised in 2015, and she enters the US Open void of confidence after slumping to a 6-0 6-1 loss to qualifier Roberta Vinci.
Bouchard has won just five matches on the WTA Tour since making the Australian Open quarter-finals.
Qualifier Yulia Putintseva dropped just four games in six sets to make the main draw, and started well against Alize Cornet - before the latter swung the match in her favour to win 2-6 6-0 6-2.
Other qualifiers Magdalena Rybarikova and Olga Savchuk were first-round winners.
Rybarikova fought back to beat Flavia Pennetta 6-7 (2-7) 6-3 6-1, while Savchuk advanced past fellow qualifier Olga Govortsova when the Belarusian retired with the score 4-6 6-3 4-0 in the Ukrainian's favour.
Savchuk's countrywoman Elina Svitolina was another to succumb to injury, with Madison Keys the beneficiary - the American progressing when leading 7-6 (7-4) 4-2.