Marketa Vondrousova, last year's Wimbledon women's champion, faced a surprising first-round exit on Tuesday, losing to Spaniard Jessica Bouzas Maneiro 6-4, 6-2.
Vondrousova, the Czech sixth seed, became the first defending women's champion in 30 years to be eliminated in the first round. "Today I was really nervous since the start. I couldn't shake it off," Vondrousova admitted.
Andy Murray, a two-time Wimbledon champion, also experienced disappointment. The 37-year-old Briton withdrew from his singles match against Czech Tomas Machac due to an injury, just as the gates opened for the second day of the Championships.
Murray had undergone surgery to remove a spinal cyst and conceded he couldn't recover in time.
Despite the setback, he might still compete in the doubles with his brother Jamie later this week.
Murray acknowledged the challenge, stating, "I may still get to write the final chapter of my fabled Wimbledon chronicle."
In contrast, Novak Djokovic began his quest for a record 25th Grand Slam title on a high note.
The Serbian, who had knee surgery after withdrawing from the French Open, showed no signs of his injury as he defeated Czech qualifier Vit Kopriva 6-1, 6-2, 6-2.
"Practice week went great but an official match on Centre Court is completely different," Djokovic said.
"I didn't know how I would feel or how the knee would hold up, but for an opening match I couldn't ask for a better start."
Top seed Iga Swiatek overcame a challenging first-round match against American Sofia Kenin, winning 6-3, 6-4 under the Court One roof.
"Felt a little bit rusty, but I'm happy that I'm through to the second round," Swiatek said. She noted the difficulty of transitioning surfaces, adding, "When you switch to any surface, first couple of matches are not going to be comfortable and you have to accept that."
In other matches, Russian Andrey Rublev, the sixth seed, lost to Francisco Comesana of Argentina 6-4, 5-7, 6-2, 7-6(5).
Rublev, frustrated with his performance, thumped his racket into his leg.
French Open runner-up Alexander Zverev made light work of Spain's Roberto Carballes Baena, and Polish seventh seed Hubert Hurkacz eased past qualifier Radu Albot.
Elena Rybakina, the women's champion in 2022, started strong by defeating qualifier Elena-Gabriela Ruse.
American fifth seed Jessica Pegula dropped only two games in her victory over Ashlyn Krueger.
Britain's number one Katie Boulter also secured a win over the experienced Tatjana Maria.
Vondrousova's loss was particularly notable as she had become the first unseeded woman to win the women's title last year.
Despite being troubled by a hip injury, she refused to blame it for her defeat.
Her opponent, Bouzas Maneiro, marked her first Grand Slam victory at the perfect time.
Light rain disrupted play occasionally but did not interfere significantly with the matches.
As the tournament progresses, fans will be eager to see how the players adapt and compete on the grass courts of Wimbledon.
(With inputs from Reuters)