Andy Murray has revealed that he found it "tough" against Russian opponent Mikhail Youzhny in the fourth round of Wimbledon on Monday.
The Scot booked his place in the last eight with a three-set win over the experienced Youzhny, but Murray insists that he is not taking anything "for granted".
"It was a tough match, the first couple of sets especially, but once I got ahead in the third I concentrated hard on not letting him back in like I did in the second set," he told BBC Sport.
"I don't take anything for granted. I know how hard these tournaments are to win. There are no guarantees here and I don't come into them thinking I am going to win.
"I think a few rounds ago I was more nervous but today I felt calmer before the match. I just concentrate on each game. Serena [Williams] lost today, Roger [Federer] has lost and Rafa (Rafael Nadal) has lost, so you cannot take anything for granted."
Murray was beaten in the final of Wimbledon last year.
