Kei Nishikori has advanced to the US Open semifinals after an epic five-set win over world No.2 Andy Murray.

Nishikori won the match 1-6 6-4 4-6 6-1 7-5, ending a brilliant run of form from Murray which saw him win Wimbledon, the Rio Olympics, Queen's Club and Rome.

The No.6 six seed will meet either Stan Wawrinka or Juan Martin del Potro in the semifinals.