Murray finding his best form

Andy Murray believes he is rediscovering his best form after reaching the US Open quarter-final with a 7-5 7-5 6-4 victory over Jo-Wilfried Tsonga.

The Scot had been forced to work for wins earlier in the tournament, but made few errors in a dominant display against the Frenchman and set up a showdown against Novak Djokovic.

Murray had not beaten a top-10 player since his emotional victory over Djokovic a year ago in the Wimbledon final, but feels he is ready to challenge for another grand slam trophy.

"I don't feel like I'm that far away from playing my best tennis," said the eighth seed.

"It's still obviously a long way from trying to win the tournament but it's only nine sets now, three matches, and I'll just try and take it one set at a time.

"I'm maybe five, six days away from potentially winning another grand slam. I know there is a lot of work to be done between now and then, but I'm putting everything out there on the courts. It's the last slam of the year. I hope I can play well."

Top seed Djokovic stands in the way of Murray's bid to repeat his US Open triumph of 2012, although Murray will take plenty of positives from his performance against Tsonga.

"Winning matches does build confidence. I played against some very good players this year and lost a few close matches," he said.

"How big is it? I don't really know, to be honest. I hadn't thought that much about it. But I'll just try and take the confidence that I gained from a win like this into the next round, and hopefully put on another good performance."

Murray handled the hot and humid conditions well, with no recurrence of the cramp issues that hampered him during a first-round win over Robin Haase.

"It was obviously extremely humid," he said. "But sometimes it depends on the day. I don't know if the conditions today were harder than they were last Monday. They felt harder.

"Last Monday I just had a terrible day. I don't know exactly what happened. I don't know why it happened. Obviously a lot of players have struggled since then."