LONDON — American 15-year-old Cori Gauff made a big early statement at Wimbledon on Monday with a 6-4, 6-4 first-round win over seven-time Grand Slam champion Venus Williams.

Gauff became the youngest-ever female qualifier at Wimbledon this year, while Williams was the oldest player in the draw at 39 years old.

“I literally got my dream draw,” said Gauff after admitting that Williams was one of her idols. “I’m just super happy I was able to pull it out today. I never expected this to happen.”

Williams won four of her seven major championships before Gauff was even born, in 2004, and the 24-year age gap between them is the biggest since a 43-year-old Kimiko Date lost to Belinda Bencic, 16, at the 2014 Australian Open.

“She did everything well today,” Williams said in compliment to Gauff. “I think the sky’s the limit for her, it really is.”

The Atlanta-based teen secured the first break for a 4-2 head start and rallied to win the first set in 32 minutes after Williams dumped a return into the net.

In the second set, both players faulted behind their serves to trade breaks and remain even at 4-4.

Gauff roared after she stretched for a winner at the net and watched the return from Williams sail long to offer her an opportunity to serve for the match at 5-4.

“I knew it was going to be mine,” said Gauff. “I was not thinking about Venus. I was just playing my game. No matter who I play against, I want to win.”

Three match points went by before Gauff sank to her knees when Williams wilted with another failed return.

After the waves of courtesy and thank-you’s to the Court One crowd, Gauff knelt by her courtside chair and prayed.

“Before every match, since I was 8, my dad and I say a prayer together,” added Gauff. “I was just thanking God for this opportunity.”

Gauff will next meet Slovakia’s Magdalena Rybarikova after she knocked out 10th seed Aryna Sabalenka with a 6-2, 6-4 victory.

There was another shock on day one in the women’s draw as Australian and U.S. Open champion Naomi Osaka was stunned 7-6 (7-4), 6-2 by Kazakhstan’s Yulia Putintseva.

On the men’s side, defending Wimbledon champion Novak Djokovic survived some early challenges before prevailing against Germany’s Philipp Kohlschreiber with a 6-3, 7-5, 6-3 victory in the opening defense of his title on Monday.

As a result, Djokovic maintained a stellar record of first-round matches at grand slam events, where he has not fallen at the first hurdle since the 2006 Australian Open.

The world No. 1, who is aiming for his fifth championship at the All-England Club, double-faulted before his serve was broken in the opening game.

“Of course, the first match, you slip few times,” said Djokovic. “The break in the first game wasn’t the start that I was looking for. There’s a lot happening obviously when you step into the court as defending champion.

“But still I’m a human being as anybody else. I do feel nerves.”

Djokovic roared after breaking Kohlschreiber in the 11th game of the second set to erase any doubts about him.

In the third set, the star 32-year-old paved his way for victory with a break at 3-3 and secured his second-round place with a cross-court forehand after two hours and two minutes.

Djokovic will play Denis Kudla in the second round after the U.S. player’s 6-4, 6-1, 6-3 victory over Tunisian Malek Jaziri.

The men’s draw saw two early exits of top seeds on day one with the dismissal of German sixth seed Alexander Zverev and seventh seed Stefanos Tsitsipas of Greece.

Zverev lost 4-6, 6-3, 6-2, 7-5 to Czech Jiri Vesely, while Tsitsipas saved two match points before falling in five sets 6-4, 3-6, 6-4, 6-7 (8-10), 6-3 to Italian Thomas Fabbiano.