United States

Serena tunes up with Federer clash with winning return

(CNN)The two tennis legends have won 43 grand slam singles titles between them and are considered by many to be the greatest of all time.But in careers lasting over 20 years Roger Federer and Serena Williams have never faced each other in a competitive match, until their eagerly-anticipated New Year's Day clash at the Hopman Cup in Perth.Williams came safely through her first official outing since her controversial US Open final loss with a straight sets win over Maria Sakkari of Greece Monday.Despite a 7-6 6-2 win for Williams, the United States fell to a 2-1 loss to Greece, making Tuesday's clash with Federer's Switzerland a must win for the six-time champions in the mixed team competition.Sealed with an ace.@serenawilliams makes a winni ...