Kei Nishikori advanced to the semifinals of the Mexico Open on Thursday with a 6-4, 6-4 quarterfinal victory over Ukraines's Alexandr Dolgopolov.
Nishikori, the top seed, knocked off his fifth-seeded opponent in 1 hour, 41 minutes, fending off four of the break points he faced.
A victory in the semifinals over 15th-ranked South African Kevin Anderson would see Nishikori move up to a career-high ranking of No. 4 in the world. Anderson advanced with a 3-6, 6-3, 6-3 victory over Viktor Troicki.