"He played the important points better than me. ... He deserved to win," said Sinner, who is ranked 23rd. "These days happen."

The 309th-ranked Draper, who hit 11 aces on Monday, was the 2018 boys' runner-up at Wimbledon. The young Englishman said he hopes this victory over Sinner improves his chances of receiving a wild card to play at the All England Club, where the next grand slam tournament begins June 28.

The left-hander's only previous tour-level match came at the Miami Open in March, when he retired because of a heat-related illness after dropping the opening set.

Since then, Draper said, he tore an abdominal muscle and "only started serving about three days ago."

Sinner is considered one of the leading up-and-coming players in men's tennis. He reached the quarterfinals of the French Open last year and the fourth round there last week - losing to 13-time champion Rafael Nadal each time.

"He's the best player in our age group, so I was quite nervous going onto the court," said Draper, who lost his opening match in qualifying at Queen's Club in 2019.

"But after I settled in, and after I played quite a few points, I felt like the crowd helped me."

In other first-round action Monday, Australia's John Millman withstood 27 aces from Reilly Opelka and edged the American 7-6 (4) 5-7 7-6 (6) .

Cameron Norrie hit 14 aces in a 4-6 6-3 6-4 victory over Albert Ramos-Vinolas, and Adrian Mannarino eliminated Liam Broady 6-4 6-4.

Australian Associated Press