AP Photo/Kirsty WigginsworthRoger Federer won the first set despite a difficult test. He then beat Lorenzo Sonego 7-5, 6-1, 6-2 to reach the quarterfinals of the 2021 Wimbledon gentlemen’s tournament.Federer became the oldest man's tennis player to reach a Grand Slam quarterfinal for 44 years.The first set was tied 5-5. Weather intervened to give both players a short rain delay and allow the retractable roof to close over the Centre Court.Sonego appeared to be on the brink of taking over the game at the time of the delay. Sonego, 26, was leading 40-15 at one time in the 11th round before play was stopped.Federer recovered from the delay and took control of the match. Sonego made several mental errors in the first set, which cost him.In the opening set, Federer was not at his best. Federer, the eight-time Wimbledon champion, made 17 unforced mistakes compared to Sonego's nine.Federer began to feel more at ease after he had completed the first set in less than an hour. The second set took him 44 minutes.Federer's 6-4 win in the second set was more consistent with what his fans have come to expect. Federer, 39, won 12 of his 15 first serve points and 11 net points. He also committed four unforced mistakes.Federer's third set featured a lot more of the same. Federer had twice as many aces (two) in the third set as in the first two. He also won two of four break-point opportunities.Federer is careful to control his playing time at this stage in his career. After a third round win, Federer withdrew from France Open because he "it important that I listen my body" after two knee surgeries.After Federer had played a four-set match with Dominik Koepfer, which lasted for 3.5 hours, the decision was taken.Federer seemed like he was in for a tough day after the first set Monday finished in 61 minutes. Federer won his next two sets in just 70 minutes.Next up for Federer is the Daniil Medvedev -Hubert Hurkacz winner.