It was the first Grand Slam singles match of Gauff’s career, and it made quite an impression on those who watched from near and far, including Williams, a five-time Wimbledon singles champion. Two of those titles came before Gauff was born on March 13, 2004, in Delray Beach, Fla.

“I think the sky’s the limit, it really is,” said Williams, who was unseeded at age 39 .

In a sense, it was her own family’s fault that an exceptional young American talent like Gauff was in position to defeat Williams on Monday.

Gauff’s father, Corey, was a point guard at Georgia State, and her mother, Candi, was a heptathlete and hurdler at Florida State. Cori might well have gravitated to a different sport, a more widely popular sport in the United States, if Serena and Venus Williams had not been winning big titles when she was a little girl setting her priorities.

Gauff chose tennis (she also liked the skirts, her father said), and it was hard not to agree with the decision on Monday as she slammed bold first and second serves under pressure, leaned into groundstrokes and covered the court with the same sort of gap-closing speed displayed by Venus Williams in her youth.

Until Monday, Gauff’s most extended contact with Williams was as a hitting partner with the United States Fed Cup team in February 2018. While Williams played, Gauff attended team dinners and cheered. Much has changed in a little more than 16 months.