Kukushkin retires to send Murray through

Andy Murray advances to the quarter-finals of the Australian Open as opponent Mikhail Kukushkin retires with a left hip flexor problem after just 49 minutes while trailing 6-1 6-1 1-0.

Murray, who will now face Japan's Kei Nishikori in the quarter-finals, described the match as "boring" because he "didn't have to do anything".