Gauff served superbly to reach her first Grand Slam quarterfinal with a 6-3, 6-1 victory over Ons Jabeur on Monday.
She also had a quick match in the previous round, when Jennifer Brady retired with an injured left foot after Gauff won the opening set.
Kenin is the highest-seeded woman left in the women’s draw at No. 4. The American lost last year’s final at Roland Garros to Iga Swiatek, who meets Marta Kostyuk in the night match on Court Philippe Chatrier.
On Sunday, Williams lost to Elena Rybakina 6-3, 7-5.
Gauff already announced herself as a contender to become the next great American player when she made a run to the fourth round at Wimbledon as a 15-year-old qualifier two years ago. Now, having gone one step further, she became the youngest American to reach a Grand Slam quarterfinal since Venus Williams did it at 17 at the 1997 US Open.
What’s more is that Gauff has not dropped a set in Paris this year.
It’s been a breakthrough year in singles for Krejcikova, 25, who won her first WTA title in Strasbourg in the buildup to the French Open. Her victory over Stephens on Court Suzanne Lenglen extended her current winning run to nine matches.
Until now, Krejcikova was mainly known for her doubles accomplishments. She is a former No. 1 in the specialty and has won two Grand Slam titles with teammate Katerina Siniakova. They play in the doubles quarterfinals on Tuesday.
Stephens committed 26 unforced errors against Krejcikova.