WIMBLEDON, England — Coco Gauff grew up admiring the Williams sisters. Picked up a tennis racket as a little girl because of them. And on Monday at Wimbledon, still just 15, Gauff beat one of them.

Gauff, the youngest competitor to qualify at the All England Club in the professional era, showed the poise and power of a much older, much more experienced player, pulling off a 6-4, 6-4 victory in the first round over Venus Williams, who at 39 was the oldest woman in the field.

When it ended, Gauff dropped her racket and put her hands on her head. After a handshake and exchange of words at the net with Williams, Gauff knelt by her sideline chair and tears welled in her eyes. Up in the stands, her father leaped out of his seat.

"Honestly, I don't really know how to feel. This is the first time I ever cried after a match. Or winning, obviously; I've cried after a loss before," said Gauff, who is based in Florida. "I don't even know how to explain how I feel."

This was her third tour-level match; Williams has played more than 1,000. This was Gauff's first match at Wimbledon, where Williams has played more than 100 and won five titles. By the time Gauff was born in 2004, Williams already had spent time at No. 1 in the rankings and owned four of her seven Grand Slam singles trophies.