US Open: Madison Keys of US and Kei Nishikori of Japan enter semifinals

In the US Open, Kei Nishikori of Japan in men's singles and Madison Keys of US in women's singles have entered the semifinals on Thursday. 

Nishikori defeated seventh-seeded Croatian Marin Cilic in a five-set match 2-6, 6-4, 7-6, 4-6, 6-4. Nishikori will play the winner of fourth quarterfinal currently underway between Serbia's Novak Djokovic and Australian John Millman.

In women singles, the American Madison Keys, defeated Carla Suarez Navarro, 6-4, 6-3. The 14th seed, Keys, will



take on 19th seed, Naomi Osaka of Japan in the semi-final. 

20-year-old Osaka defeated unseeded Ukrainian Lesia Tsurenko, 6-1, 6-1 to become the first Japanese woman to reach a Grand Slam semifinal in more than two decades.

Spain's Rafael Nadal and Argentina's Juan Martin Del Potro in men's singles and American Serena Williams and Latvian Anastasija Sevastova in women's singles have already entered the semifinals.