Ben Shelton beat fellow American Frances Tiafoe 7-6(2) 6-4 in an electrifying match at the Washington Open on Friday to advance to the semifinals on a day marked by suffocating humidity in the nation's capital.

Ben Shelton and Frances Tiafoe met in the quarter-final of the home ATP 500 event in Washington. The younger American scored a 7-6, 6-4 victory in an hour and 57 minutes, beating his good friend for the third time in four duels.