NEW YORK (Reuters) - Serena Williams and Ekaterina Makarova sprinted into the semi-finals of the U.S. Open on Wednesday, while world number one Novak Djokovic and marathon man Kei Nishikori were forced to take the long road into the last four.
Having already played the longest match of the tournament in the fourth round, a bruising four-hour 19-minute battle with Canadian Milos Raonic, Nishikori had enough left in the tank to get past third seed Stan Wawrinka 3-6 7-5 7-6 (7) 6-7 (5) 6-4 in a four-hour 15-minute test of wills to become the first Japanese man into the last four of a grand slam in 81 years.