Eight-time Wimbledon champion Roger Federer may have only been a Centre Court guest but his huge aura was still felt by those competing on Tuesday.
Defending women's champion Elena Rybakina said Federer's presence - for a ceremony to mark his achievements - had made her "nervous".
Men's top seed Carlos Alcaraz was "a little bit jealous" after missing out on being watched by the retired Swiss.
Andy Murray, meanwhile, got a nod of approval from one of his great rivals.
"It was amazing to have some royalty here and some tennis royalty as well," Murray said of Federer, who was sitting next to the Princess of Wales. "It's amazing to have Roger here supporting the event.
"The last time I was on this court and he was watching it, it was the [2012] Olympics and he was sat in Stan Wawrinka's box supporting against me. [Roger,] I hope you are doing well."
Federer took the acclaim of an adoring Centre Court crowd in the special ceremony on day two of the grass-court major to mark his success at the tournament.
The 20-time Grand Slam champion, returning after retiring last year, received a long ovation as he descended the steps of the Royal Box, where he had been invited as a special guest to watch the action.
The Swiss, 41, won five successive Wimbledon titles between 2003 and 2007, adding further victories in 2009, 2012 and 2017.
His win six years ago saw him pass Pete Sampras' men's record of seven titles.
Those with a ticket for Centre Court were treated to a video montage on the big screen which showed Federer through the years - from his first Wimbledon title win through to his last.
Federer then received a guard of honour in the Royal Box, smiling and waving to the crowd as they applauded and cheered one of the greatest players of all time.
With 103 ATP titles to his name and having spent 310 weeks as world number one, Federer is much loved by the British crowds and the standing ovation lasted several minutes.
The 15,000 or so expectant fans may have been disappointed Federer did not speak, with play getting under way immediately after the announcer thanked Federer for the memories he has provided Wimbledon fans over the years.
But he did not have to speak to have an impact.
It was not that Rybakina did not want him there to see her open her title defence against American Shelby Rogers, it was just that she was rattled by his presence as she even double-faulted on the first point.
"Maybe that's why I was nervous because actually I really like Roger," the Kazakh said after fighting back from a set down to win. "When I was younger, I was always watching him play."
But one man who wished Federer had been on his court was Alcaraz, who was in electrifying form on Court One in his victory over Jeremy Chardy.
"I saw that Roger Federer was here. I was a little bit jealous," Alcaraz said with a smile. "Honestly, I want Roger Federer to watch one of my matches obviously.
"I wish to talk a little bit with him. For me [it would] would be amazing. I hope to see him around more than once."
Murray, meanwhile, has played Federer many times over the years including a loss to the Swiss in the 2012 Wimbledon final which preceded Murray's victory over him a few weeks later in the Olympic final at the same venue.
At the end of Murray's first-round victory over fellow Briton Ryan Peniston, Federer was asked whether he approved of the performance, to which he nodded, prompting laughter from the crowd.
Seven-time women's singles champion Serena Williams, who retired last year too, had also been invited by the club, but the pregnant 41-year-old was unable to travel.