Australian Nick Kyrgios saved five matchpoints during a dramatic second-set tie-breaker to edge local hope Frances Tiafoe 6-7(5) 7-6(12) 6-2 and reach the semi-finals of the Citi Open in Washington.
The Wimbledon runner-up appeared set for an exit when Tiafoe set up an opportunity to serve for the win during the second set tiebreaker, but Kyrgios won the point and saved four more chances on his own serve to frustrate the American.
