Serena Williams, 44, and Carlos Alcaraz defeated Erin Routliffe and Lloyd Glasspool 5-3, 4-1 in the first round of US Open mixed doubles and advanced to the quarterfinals. Novak Djokovic and Aryna Sabalenka lost their opening match 1-4, 4-2, 10-2 to Henry Patten and Katerina Siniakova. The mixed doubles event is held the week before the singles main draw begins August 30.