Nishikori books quarters spot

New York - Japanese sixth seed Kei Nishikori reached the US Open quarter-finals on Monday with a 6-3, 6-4, 7-6 (7/4) win over big-serving Ivo Karlovic.

Nishikori, the runner-up in 2014, will face either second seed and 2012 champion Andy Murray or Grigor Dimitrov of Bulgaria for a place in the semi-finals.

Results from the eighth day of the 2016 US Open tennis championships at Flushing Meadows on Monday (x denotes seeded player):

Men

Fourth round

Juan Martin Del Potro (ARG) bt Dominic Thiem (AUT x8) 6-3, 3-2 - retired

Stan Wawrinka (SUI x3) bt Illya Marchenko (UKR) 6-4, 6-1, 6-7 (5/7), 6-3

Kei Nishikori (JPN x6) bt Ivo Karlovic (CRO x21) 6-3, 6-4, 7-6 (7/4)

Andy Murray (GBR x2) bt Grigor Dimitrov (BUL x22) 6-1, 6-2, 6-2

Women

Fourth round

Serena Williams (USA x1) bt Yaroslava Shvedova (KAZ) 6-2, 6-3

Simona Halep (ROM x5) bt Carla Suarez Navarro (ESP x11) 6-2, 7-5

Ana Konjuh (CRO) bt Agnieszka Radwanska (POL x4) 6-4, 6-4

Karolina Pliskova (CZE x10) bt Venus Williams (USA x6) 4-6, 6-4, 7-6 (7/3)