Novak Djokovic moved into the U.S. Open semifinals for the 10th consecutive year when No. 9 Jo-Wilfried Tsonga stopped because of a hurt left knee, the defending champion’s third opponent to pull out with an injury. After the top-seeded Djokovic won the first two sets 6-3, 6-2 on Tuesday night, Tsonga was visited by a trainer and had his left leg taped below the knee. Tsonga double-faulted on the opening point of the third set, then retired from the match. Djokovic’s second-round opponent, Jiri Vesely, withdrew from the tournament with a sore left forearm. The man Djokovic was supposed to play in the third round, Mikhail Youzhny, quit after six games because of a strained left hamstring. Earlier, Monfils, Wozniacki and Kerber won their respective quarter-final matches to book a place in the last-four.
[US Open 2016, Day 9: Novak Djokovic, Monfils, Kerber, Wozniacki through to semis[/b]