Sloane Stephens revived American interest at the French Open as she swept past the challenge of Slovenia's Polona Hercog, winning 6-1 6-3 in just 74 minutes.
Her win came a day after defending champion and top seed Serena Williams and sister Venus were both dumped out of the tournament.
That left Stephens, the No 2 ranked American, as the main flag-bearer for her country with Alison Riske and Coco Vandeweghe also in second round action on Thursday.
In the other half of the draw 18-year-old wildcard Taylor Townsend is already through to the third round, upsetting 20th seeded Frenchwoman Alize Cornet on Wednesday.
Seeded 15th, Stephens was solid on serve apart from a brief blip in the second set when Hercog broke to get to 4-3, and she has yet to drop a set having defeated tough Chinese player Peng Shuai in the first round.
She will play 22nd seed Ekaterina Makarova of Russia for a place in the last 16.
Stephens enjoyed a breakthrough year in 2013 highlighted by a semi-final appearance at the Australian Open, a run into the quarter-finals at Wimbledon and fourth round spots at both the French and US Open.
That left her ranked 12th in the world at the end of the year and set to break into the top 10 this year.
In other action, Serbian sixth seed Jelena Jankovic was given a stern text in the opening set before coming through against Kurumi Nara from Japan 7-5 6-0 on Court Philippe Chatrier.
The 2009 Roland Garros champion Svetlana Kuznetsova also reached the third round after victory against Italy's Camila Giorgi 7-6 (7/5) 6-3.
She will take on either fifth seed Petra Kvitova in the third round after the former Wimbledon defeated Marina Erakovic 6-4 6-4.
New French hope Kristina Mladenovic, who beat Li Na in the first round, continued her crowd-pleasing run with a 7-6 (7-5) 3-6 6-3 win against Alison Riske.
Former finalist Sara Errani is also through to the third round after beating Dinah Pfizenmaier 6-2 6-4.