Knee surgery and a nagging back injury had restricted the 17-times grand slam champion to 22 matches this season and his no-show at the recent French Open ended a run of 65 consecutive major appearances.
Talk of time finally catching up with Federer has been doing the rounds. So all eyes were on the 34-year-old Swiss great as he stepped onto Centre Court where he had held the trophy aloft on seven occasions.
But Federer began his 18th consecutive Wimbledon campaign with a tidy 7-6(5) 7-6(3) 6-3 victory that, while never spectacular, was relatively comfortable.
He offered up not a single break point to the 51st-ranked Pella, and while he converted only one of the nine that came his way, he found an extra gear when required.
Federer's only real moment of alarm came at 5-6, 0-30 in the second set. But he quickly killed the danger and waltzed through the tiebreak to take a two-set lead. With light fading he made light work of the third set.
Federer's next appointment will be with British qualifier Marcus Willis, ranked 772nd in the world, on Wednesday.