Fritz, Townsend face difficult tests at US Open, Djokovic battles injuries

Fritz's own road to the fourth round has been rocky, as he dropped a set in his last two matches against Lloyd Harris and Jerome Kym, with the latter taking him to tiebreaker twice.

US OPEN: The U.S. Open enters its fourth round on Sunday, with American hopes Taylor Fritz and Taylor Townsend facing tough tests as Novak Djokovic battles through injuries to continue his quest for a record 25th slam. Pic: AP Photo/Antonio Calanni

The U.S. Open enters its fourth round on Sunday, with American hopes Taylor Fritz and Taylor Townsend facing tough tests as Novak Djokovic battles through injuries to continue his quest for a record 25th slam.

Last year's finalist Taylor Fritz remains the home nation's best hope of becoming the first American man since 2003 to win the U.S. Open title following the exits of sixth seed Ben Shelton and 17th seed Frances Tiafoe in the third round.