Nishikori into US Open quarter-finals
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.