Federer and Williams cruised into the third round with straight-sets victories on Wednesday, looking at home on the Centre Court where they have won 15 titles between them.
The Bulgarian offered a little more fight in the second, but only after conceding an early break that she would fail to recover from, and the seven-time Wimbledon victor had it wrapped up in 66 minutes.
Certainly, not many here will be fooled by her world ranking of 181, least of all the player placed 46 spots higher in those standings, Tomova.
The last time Federer turned up to defend his crown, in 2013, he suffered a shock second-round humbling by Sergiy Stakhovsky.
"I did everything I could", Wozniacki said afterwards.
"Of course, you sometimes play the percentages, but if you do that too much it becomes boring, so I like to mix it up". Federer also commented on how he felt during his first round match win against the Serb Dusan Lajovic, playing as first on Centre Court: 'It was good.
The 38-year-old American brought her experience to bear from the second set to seal a comfortable win in her first meeting with the Romanian.
"I was really nervous, because you need to win this point. I want to be here to focus on tennis, not eating bugs", she said to the umpire. But for now, they are still here, both getting ready to play third-round matches on Friday.
The third set was one-way traffic as Federer killed the contest with a ferocious forehand after 90 minutes of brilliance.
Serena Williams reached the third round at Wimbledon 2018.
The Dane fought to the bitter end against the tenacious Russian, but she finally succumbed on the sixth match point after an absorbing clash lasting two hours and nine minutes.
British teenager Katie Swan, who won her first ever match at Wimbledon on Monday, was no match for 29th seed Mihaela Buzarnescu as the 19-year-old fell to a 6-0 6-3 defeat.
"I don't know. I don't know, " he began, before offering quite a list for someone who doesn't know.
"I wake up early, something I never did, to spend time with her".
Former finalist Agnieszka Radwanska lost 7-5, 6-4 to Czech world number 66 Lucie Safarova.