Roger Federer celebrated the New Year in style with a 6-4, 6-1 win over Frances Tiafoe to give defending Hopman Cup champion Switzerland an early lead over the United States, ahead of his showpiece mixed doubles game featuring fellow tennis great Serena Williams. The 37-year-old Federer was made to work during a tough first set before overwhelming the 20-year-old Tiafoe and taking control of the contest by winning seven straight games. Federer needed just 57 minutes to claim his fourth straight victory over the rising American player. ``I played another good match. I'm really happy,'' Federer said. ``It is a great start to the season for me. I made sure I kept focused on my serve and he gave me some errors at the end of the first set.'' Williams next plays Belinda Bencic in the women's singles of the Group B match, followed by the eagerly awaited mixed doubles pitting Federer and Williams against each other for the first time. The U.S. lost to Greece on Monday, while Switzerland has continued its perfect start after sweeping Britain in its opener. Federer had a masterclass win over British player Cameron Norrie in his opening match and has lost just seven games in his first two matches of the round-robin tournament. Federer found his groove in a scintillating second set with the 20-time Grand Slam singles champion unleashing several trademark backhand winners. He broke a beleaguered Tiafoe three times to issue an ominous early statement to his rivals. Federer's appearances at the past two Hopman Cups laid the groundwork for successful Australian Open campaigns. (For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)