World number two Andy Murray has insisted that he remains "proud" of his achievements despite exiting the US Open at the quarter-final stage after being beaten by Japan's Kei Nishikori.
Murray, who claimed an Olympic gold and a second Wimbledon title earlier in the summer, suffered his earliest Grand Slam defeat of the season following a 1-6 6-4 4-6 6-1 7-5 loss on Wednesday evening.
"I tried my best. I fought as as hard as I could with what I had today," said Murray, according to BBC Sport.
"I pushed myself as hard as I could over the last few months and I'm very proud of how I've done."
The defeat was just the second that Murray has suffered in 28 matches.
