New York - American 14th seed Madison Keys reached a second successive US Open semi-final on Wednesday with a 6-4, 6-3 win over Spain's Carla Suarez Navarro.
Keys, 23, lost in the final of the 2017 tournament to compatriot Sloane Stephens.
To return to the final she will have to defeat Japan's Naomi Osaka in Thursday's semi-finals.
Six-time champion Serena Williams faces Latvia's Anastasija Sevastova in the other semi-final.
US Open results on Wednesday, the 10th day of the 2018 tournament at Flushing Meadows (x denotes seeded player):
Kei Nishikori (JPN x21) bt Marin Cilic (CRO x7) 2-6, 6-4, 7-6 (7/5), 4-6, 6-4
Novak Djokovic (SRB x6) bt John Millman (AUS) 6-3, 6-4, 6-4
Madison Keys (USA x14) bt Carla Suarez Navarro (ESP x30) 6-4, 6-3
Naomi Osaka (JPN x20) bt Lesia Tsurenko (UKR) 6-1, 6-1