Sloane Stephens revived hopes of a US winner at the French Open on Thursday as she swept past the challenge of Slovenia's Polona Hercog, winning 6-1, 6-3 in just 74 minutes.
The win came on the day after title-holder and top seed Serena Williams and her big sister Venus were both dumped out of the tournament in shocking style.
With Alison Riske and Coco Vandeweghe both losing their second round ties on Thursday, Stephens is one of only two Americans left in the tournament.
In the other half of the draw 18-year-old wildcard Taylor Townsend made it through to the third round, on Wednesday by upsetting 20th seeded Frenchwoman Alize Cornet.
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 next plays Ekaterina Makarova of Russia, who defeated Vandeweghe, 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 Opens.
That left her ranked 12th in the world at the end of the year and set to break into the top 10 this year.
She won through to the fourth round in the Australian Open, but had first round losses at both Dubai and Doha before reaching the quarter-finals at Indian Wells and the third round in Miami.