Fans during the match between Stefanos Tsitsipas and Alexander Bublik. EPA
Serbia's Novak Djokovic reacts after winning the match against Germany's Philipp Kohlschreiber during the Dubai Duty Free Tennis Championships on Wednesday. AFP
Novak Djokovic beat Philipp Kohlschreiber to enter the quarter-finals. Reuters
Germany's Philipp Kohlschreiber returns to Serbia's Novak Djokovic during the Dubai Duty Free Tennis Championships. AFP
Japan's Yasutaka Uchiyama during his second round match against France's Gael Monfils. Reuters
Gael Monfils of France returns the ball to Japan's Yasutaka Uchiyama in Dubai. AP
Stefanos Tsitsipas of Greece hits a forehand against Alexander Bublik of Kazakhstan during the Dubai Duty Free Tennis Championships. Getty Images
Alexander Bublik of Kazakhstan during the match against Stefanos Tsitsipas. Getty Images
Fans during the match between Stefanos Tsitsipas and Alexander Bublik. EPA
Serbia's Novak Djokovic reacts after winning the match against Germany's Philipp Kohlschreiber during the Dubai Duty Free Tennis Championships on Wednesday. AFP
Novak Djokovic beat Philipp Kohlschreiber to enter the quarter-finals. Reuters
Germany's Philipp Kohlschreiber returns to Serbia's Novak Djokovic during the Dubai Duty Free Tennis Championships. AFP
Japan's Yasutaka Uchiyama during his second round match against France's Gael Monfils. Reuters
Gael Monfils of France returns the ball to Japan's Yasutaka Uchiyama in Dubai. AP
Stefanos Tsitsipas of Greece hits a forehand against Alexander Bublik of Kazakhstan during the Dubai Duty Free Tennis Championships. Getty Images
Alexander Bublik of Kazakhstan during the match against Stefanos Tsitsipas. Getty Images
Fans during the match between Stefanos Tsitsipas and Alexander Bublik. EPA