Swiss Federer, the record eight-times All England Club champion, was the guest of honour on the show court as Rybakina began her title defence in uncertain fashion by dropping the first set before beating American Shelby Rogers (30) 4-6, 6-1, 6-2.
Rybakina, who also came from a set down to beat Ons Jabeur in the final last year, said experience counted for nothing when you have a sporting icon watching your every move.
"Yeah, maybe that's why I was nervous because actually I really like Roger. When I was younger, I was always watching him play," the Kazakh told a press conference.
"The year after, to be again on this court with the same crowd, it was really special.
"First matches, I think they're always tough I would say, like, mentally to get to the rhythm of the tournament. So hopefully the next match is going to be easier."
The first set was where Rybakina looked to have suffered from having almost zero preparation on grass. Illness forced her to withdraw from the French Open in the third round and she missed a warm-up event in Eastbourne.
However, she quickly regained her rhythm and the third seed will look to become only the second woman in the past 10 years to win back-to-back Wimbledon titles after Serena Williams in 2015 and 2016.
"Physically. I'm feeling good. Of course, maybe I'm missing a bit some things here and there because we didn't put enough hours or maybe the hours we wanted to do," Rybakina said.
"But overall I feel good. I think with every match, I'm going to just also get in physically more ready for all the matches."
Jealous Alcaraz
Carlos Alcaraz (20) made an almost perfect start to his Wimbledon title quest on Tuesday with the only thing missing being the presence of Federer in the Court One stands.
Had Federer been present, he surely would have been impressed by the ferocity of top seed Alcaraz's game as he swiped 25 baseline winners in a little under two hours to dispatch Frenchman Jeremy Chardy 6-0, 6-2, 7-5.
"I saw that Roger Federer was here. I was a little bit jealous," Alcaraz, who, despite oozing confidence on court, remains humble in the extreme, told reporters.
"I want Roger Federer to watch one of my matches, obviously. I wish to talk a little bit with him. For me, would be amazing. I hope to see him around more than once."
It is unclear how long the retired Federer is in town, but if he is sticking around he will surely want to get a court-side view of the man being labelled the future of men's tennis.
Federer took until his fifth appearance to claim the Wimbledon crown in 2003 but Alcaraz made no attempt to play down his prospects of winning the title on his third attempt.
"To win the tournament. That's the main goal right now," Alcaraz, who finished off Chardy with a 10th ace, said.
"I have a lot of confidence right now. The main goal for me this tournament is to win, to win it."
US Open champion Alcaraz, who returned to world number one after winning the Queen's Club title in what was only his third event on grass, barrelled through the opening set in 20 minutes with the crowd gasping at the power of his strokes.
He did suffer a lapse in the third set, however, offering Chardy the opportunity to extend what was the last match of his long career.
But Alcaraz quickly re-focussed having slipped 4-2 behind with a sloppy service game and raced to victory.
He said that was all part of the learning curve.
"Here let's say you are not focussed for one game, like in the third set, and he breaks my serve and you are down," he said. "For me, that's something that I have to learn more."
While Alcaraz is the top seed, Novak Djokovic remains the favourite as he bids for a record-equalling eighth title at Wimbledon, especially after he beat the Spaniard in the French semi-finals in which Alcaraz suffered body cramps caused by the stress of playing the Serb.
Asked if he had any concerns about facing Djokovic again, perhaps in the Wimbledon final next week, he said: "I think I learned a lot from that match for the next time I face Novak.
"It's going to be different for me. I'm going to deal with the pressure better than I did in the semi-final of French Open."
