Top-seeded Novak Djokovic advanced to the third round at Wimbledon with a 6-1, 6-4, 6-2 victory over Thanasi Kokkinakis of Australia.
The six-time Wimbledon champion has won the past three men's singles titles at the All England Club.
The 26-year-old Kokkinakis is ranked 79th.
French Open runner-up Casper Ruud lost in the second round at Wimbledon.
The third-seeded Norwegian was beaten by Ugo Humbert of France 3-6, 6-2, 7-5, 6-4 on No. 2 Court.
Ruud was making his third appearance at the All England Club. His victory over Albert Ramos-Vinolas on Monday was his first at the grass-court Grand Slam.
Second-seeded Anett Kontaveit of Estonia was eliminated in the second round of Wimbledon, losing to Jule Niemeier of Germany 6-4, 6-0.
Kontaveit has never reached the fourth round at the All England Club, the only one of the four major tournaments in which she has failed to get that far. She was making her eighth appearance at Wimbledon.
It was Kontaveit's first match on grass this year.
On Tuesday, an off-key Nadal, already halfway to a calendar Grand Slam after winning the Australian Open and French Open, dug deep to beat Francisco Cerundolo 6-4, 6-3, 3-6, 6-4.
The two-time Wimbledon champion, who has not played at the tournament since 2019, thanked the crowd for their wholehearted support.
"It's not a surface that we play very often, and especially in my case, for different reasons, the past three years I didn't put any foot on a grass court, so it always takes a while," said Nadal, 36.
"It was my first match and as I know, every day is a test and today was one of these important tests."
out from doubles
A day after eliminating Serena Williams from Wimbledon in her debut at the grass-court Grand Slam, Harmony Tan surprised and angered her doubles partner by withdrawing from that tournament on Wednesday with a thigh injury.
Tan, a Frenchwoman ranked 115th who beat the 23-time Grand Slam singles champion 7-5, 1-6, 7-6 (10-7) on Centre Court on Tuesday, was scheduled to team with Tamara Korpatsch for their opening doubles match on Wednesday.
"She just texted this morning. Let me wait here 1 hour before the match start," Korpatsch wrote in an Instagram post. "I'm very sad, disappointed and also very angry that I can't play my 1st Doubles Grand Slam.
"And it's really not fair for me ... I didn't deserve that."
Tan is scheduled to play No. 32 Sara Sorribes Tormo of Spain in the second round of the singles tournament on Thursday. Sorribes Tormo advanced by defeating American qualifier Christina McHale 6-2, 6-1.
The 24-year-old Tan is ranked 611th in doubles and has never played in that event at Wimbledon. Korpatsch, a 27-year-old German who is ranked 298th in doubles, lost in the first round of the singles tournament but has never played a doubles match at any Grand Slam tournament.
Tan was two points from losing to Williams, a seven-time Wimbledon champion who hadn't played a singles match since injuring herself in the first round a year ago at the All England Club.
The match lasted 3 hours, 11 minutes.
"If you're broken after a 3 (hour) match the day before, you can't play professional (tennis). That's my opinion," Korpatsch wrote.
Tan and Korpatsch were scheduled to play 15th-seeded Nadiia Kichenok and Raluca Olaru on Wednesday in the first round of the doubles tournament. They were replaced in the draw by Valentini Grammatikopoulou and Peangtarn Plipuech.
charity match
Top-ranked Iga Swiatek of Poland will host a charity tennis tournament next month to raise funds for children and teenagers impacted by the war in Ukraine.
The event will be held in Krakow on July 23 and will feature a mixed doubles exhibition match. Ukraine soccer great Andriy Shevchenko will be a special guest.
Elina Svitolina of Ukraine will serve as umpire for the event. They hope to sell at least 10,000 tickets.
Swiatek has been wearing a pin with the Ukrainian colors during her matches. More than 4 million refugees crossed into Poland after Russia invaded Ukraine in February. Poland is providing them with free shelter, social and medical care, education and job opportunities.