Novak Djokovic of Serbia sits on the grass after diving to return to Miomir Kecmanovic of Serbia during a third round men's singles match at the Wimbledon Tennis Championships in London on Saturday. (AP Photo/Kirsty Wigglesworth)

LONDON (AP) — Successful as Novak Djokovic has been on the grass courts of Wimbledon — he’s won 100 matches and seven of his 24 Grand Slam trophies there — it’s not as if he grew up plying his talents on the surface.

Indeed, he never competed or even practiced on it at all until 2005, when he entered the qualifying event held at the nearby Roehampton facility and won three matches there to earn the right to make his debut at the All England Club at age 18.

“That was actually the first year I stepped out on the grass,” said Djokovic, who will play 11th-seeded Alex de Minaur today for a quarterfinal berth at the Grand Slam tournament. “I must say that it felt very natural for me to adapt to it, even though I grew up on clay.”

That’s a common refrain among today’s pros, and the lack of familiarity with, and comfort on, grass could be one of the reasons for all of the upsets in the early going at Wimbledon. The eight total top-10 seeds — four women, four men — who lost in the first round were the most at any major since they began seeding 32 in brackets in 2001.

“Grass,” 2022 champion Elena Rybakina said after her third-round exit Saturday, “is very unpredictable.”

With her departure, and defending champ Barbora Krejcikova’s loss to Emma Navarro a few hours later, there is guaranteed to be yet another first-time women’s title winner this year at the All England Club. Whoever takes home the trophy on July 12 will be the ninth woman to do so in the event’s past nine editions.

Plenty of top players learned to play tennis on hard courts, especially in North America, or clay courts, especially in Europe and Latin America. Grass? Not so much, except for those from England or Australia. It’s an acquired taste and skill, and it doesn’t help anyone that the portion of the season spent on the turf is so abbreviated.

There are more than 35 hard-court tournaments listed on the 2025 WTA calendar, 11 held on clay and seven on grass, which is used from June 9 through Wimbledon.

Naomi Osaka, a former No. 1 and four-time Grand Slam champion on the hard courts of the U.S. Open and Australian Open, slipped and hurt her knee nearly a decade ago on grass and that created fear, she said. She has never been past the third round at Wimbledon.

Iga Swiatek, another former No. 1 and the owner of five major trophies earned elsewhere, did win a junior Wimbledon title, but it’s her least-successful Slam as a pro. She will try to equal her run by getting to the quarterfinals with a victory against No. 23 Clara Tauson today.