ANDY MURRAY recorded his best win since lifting the Wimbledon trophy last year to set up a US Open last-eight clash with Novak Djokovic, the player he beat in two grand slam finals.

Murray had not beaten a top-10 player since his emotional Centre Court victory over the Serb last year but played a fine match in the New York heat to defeat ninth seed Jo-Wilfried Tsonga 7-5, 7-5, 6-4.

It maintained Murray's impressive record of having reached at least the quarter-finals of every grand slam tournament he has played in for the past four years.

Afterwards he admitted: "It was extremely tough conditions, very humid. It started to cool down a bit at the end but the first two sets were very long, tough sets and mentally quite draining. I'm glad I managed to get through."

The 27-year-old Scot will play Djokovic on Wednesday. It will be their first meeting at Flushing Meadows since Murray's maiden grand slam triumph two years ago following a five-set thriller.

"It will be a tough match," said Murray. "We've had a lot of long ones, there are normally a lot of rallies. We had a long one here a couple of years ago.

"And I obviously have great memories from that match.

"Hopefully we can play another top-level match. If I play well, I have a chance."

Murray had beaten Tsonga in nine of their previous 11 matches but lost the most recent one in Toronto last month.

Ahead of the clash the Frenchman had claimed there was no longer the same fear factor about Murray in the locker room, and he also sensed there was not the same power in Murray's serve and groundstrokes.

However, there was nothing wrong with the eighth seed's serve in the first set, Tsonga managing just three points on it. The disappointment for Murray was that he could not capitalise on Tsonga's early edginess but more chances arrived in the 12th game and he took his second set point thanks to a fine backhand return.

Things began to get sticky early in the second set, though, with Murray finding himself under pressure on serve for the first time in the third game and responding with a drop shot that limped into the net. He had two chances to level at 3-3 but was a little passive both times and was beginning to cut a frustrated figure.

THE Scot did not have to wait long for more chances, with two in the eighth game. The first was saved by Tsonga with an ace but on the second Murray sent a forehand winner into the corner.

Suddenly the 2012 champion looked the more likely winner of the set, and again he struck in the 12th game, seizing on a second serve to win it 7-5.

The conditions were tougher than when Murray cramped so dramatically against Haase last week but there was no sign of any physical discomfort here.

What was the same, however, was that Murray had a dip at the start of the third set, serving a double fault to go a break point down before Tsonga powered away a return to go ahead.

Murray had to work very hard to avoid trailing 3-0, saving two break points, and got his reward in the next game, breaking back to love to make it 2-2.

There was a bit of ranting and raving - and some choice language - but Murray kept his focus well and played the shot of the match in the sixth game, slamming a running forehand cross-court winner off a decent Tsonga smash.

The pressure was all on the Frenchman serving to stay in the match at 4-5 and he started badly with successive double faults.

Murray then nailed a backhand winner to bring up three match points. He took the second when a tired-looking Tsonga placed a backhand long after two hours and 35 minutes.