PARIS, France - A semifinalist 12 months ago, Madison Keys is back in the second week of the French Open.

The No.14 seed staved off an inspired effort from unseeded Russian Anna Blinkova in Saturday's third round on Court Simonne-Mathieu, 6-3, 6-7(5), 6-4. 

Keys was one of three Americans to win third round matches on Saturday in Paris, as Sofia Kenin authored a stunning upset of Serena Williams and 17-year-old Amanda Anisimova beat Irina-Camelia Begu in straight sets to reach the fourth round for the second consecutive Grand Slam.

From a set and a break up, Keys fended off another comeback effort by the qualifier ranked World No.117, one of many that the 20-year-old authored over her best career Grand Slam run to date.

Blinkova batted back from either a break or double-break down in the final set of four of her previous five matches over the past 11 days in Paris, and seemed primed to do so again after saving a match point to steal the second set.

Related: Blinkova scores breakthrough win over Garcia at French Open

Blinkova later ripped off three games in a row, earning parity after trailing 1-4 in the final set, and held two break points on Keys' serve for a fourth straight game and an opportunity to serve for the match.

However, big htting and timely serving saved the American when she needed it most, as she won eight of the last nine points to move safely through to the round of 16.

Following Naomi Osaka's shock defeat to Katerina Siniakova earlier on Saturday, Keys will next face the unseeded Czech with a spot in the quarterfinals on the line.

The American will look to reach the last eight at a major for the seventh time in her career, and fifth time in her last seven Grand Slam appearances.

Forced to withdraw from her scheduled doubles match yesterday with a viral illness, Anisimova closed out Saturday action as she saved two set points in the first set tiebreak before seeing off Begu, 7-6(6), 6-4.

"It feels really great to be in the second week, obviously. I'm just super happy, because today was really tough for me," Anisimova said.

"Today I didn't feel well at all. It was just super tough the whole entire match, and even my warmup. It was just a really big struggle getting through the match today and I'm just really proud I could take this win today."

The American, joined in week two by 18-year-old Iga Swiatek and 19-year-old Marketa Vondrousova, is the youngest player to reach this stage of the French Open since Martina Hingis in 1998.

"After Australia I had confidence, but going into clay, I was just looking forward to it. I didn't really have any expectations, because I didn't play on it for such a long time because I missed the clay season last year," she said.

"I'm just really happy I got this opportunity to play and I'm really happy that I have been doing well and getting wins on it, doing well in this Grand Slam. It's really nice.

"I'm still 17, so I try to savor the moment while I'm still young. It's kind of nice. There have been a lot of upsets in this tournament, so that's pretty good."

Anisimova will next face Spanish qualifier Aliona Bolsova, whose incredible Grand Slam main draw debut continued with a sixth victory in the span of a week-and-a-half.

The 21-year-old former collegiate tennis star, who's studying history, geography and art at a Spanish university, downed unseeded Russian Ekaterina Alexandrova, 6-2, 7-5.

Read more: Aliona Bolsova rising: ‘I’m just introducing myself to the world of tennis’

"I didn't know she was a qualifier, but that's great for her, getting through all the qualies and getting to the fourth round. That's really amazing," said Anisimova.

"I'm sure she's really happy with her results, and I am, too. It should be a good match, and I'm looking forward to playing against her."