Melbourne, Australia, Jan 23: Andy Murray is into the Australian Open quarterfinals after Mikhail Kukushkin retired from their fourth-round match Monday with a left hip injury.
Murray was leading 6-1, 6-1, 1-0 when the Russian-born Kazakhstan player came to the net and said he couldn't continue.
With Murray leading 4-1 in the first set, Kukushkin called for a trainer, who gave him medication.
Murray, the losing Australian Open finalist the last two years, will next play either 2008 finalist Jo-Wilfried Tsonga or Kei Nishikori of Japan.
