Elena Rybakina's comfort on clay improved as she eased into the third round at the French Open by beating another Czech teenager on Thursday. (More Tennis News)
The Wimbledon champion, the No. 4 seed at Roland Garros, beat 18-year-old Linda Noskova 6-3, 6-3 on Court Suzanne Lenglen.
"I cannot say that here it's easy for me. It's still every match getting better and better," Rybakina said on court. "It was a bit slippery for me today, I don't know why."
She ought to be feeling cosy on dirt after winning the Italian Open, but the 6-foot (1.8-meter) Kazakh is banking most of her confidence on her height advantage.
"This is my good weapon," she said, "but, at the same time, to move on clay it's not easy. It's always I need more to prepare and, of course, be more patient during the rallies."
The Australian Open runner-up hit 30 winners to Noskova's 16, though both players had 26 unforced errors.
"I was struggling a lot on her serves," the Moscow-born Rybakina said.
Rybakina, who beat Brenda Fruhvirtova in the first round, will next face Sara Sorribes Tormo of Spain.
No. 20 Madison Keys committed a whopping 74 unforced errors in her 6-2, 4-6, 6-4 loss to fellow American player Kayla Day on Court Simonne Mathieu.
The 23-year-old Day, who won the girls' title at the 2016 U.S. Open, is ranked 138th and came through qualifying to make her Roland Garros main-draw debut. She beat French wild card Kristina Mladenovic in the first round.
Later, defending champion and No. 1 seed Iga Swiatek faces Claire Liu of the United States. Coco Gauff — last year's runner-up — takes on Julia Grabher of Austria.
Top men in action include two-time major finalist Casper Ruud, No. 8 Jannik Sinner and No. 12 Frances Tiafoe.
No. 18 Alex de Minaur of Australia lost to Tomas Martin Etcheverry of Argentina 6-3, 7-6 (2), 6-3.