Djokovic batters Fish at Flushing Meadows

Novak Djokovic has warned his rivals he is getting better by the round after setting up a US Open quarter-final with France's Gael Monfils.

Monfils reached the last eight of the US Open for the first time in his career with a straight-sets victory over compatriot Richard Gasquet.

But Djokovic was also a winner in straight sets, the Serbian third seed enjoying a surprisingly easy victory over American Mardy Fish.

Fish has been in excellent form during the US hard court circuit this summer, but Djokovic was always in command as he eased to a 6-3 6-4 6-1 win in just one hour and 50 minutes.

‘I was serving well and using the court well and overall I am very happy with the way I played,’ said Djokovic, who came from two sets to one down against Davis Cup team-mate Viktor Troicki in the first round but has not dropped a set since.

‘It gives me a lot of confidence. It's great to raise the level of performance towards the end of the tournament. It's been a great couple of years for me in New York (runner-up in 2007, semi-finalist the last two years), so hopefully I can go on.’

Fish, who won back-to-back tournaments for the first time in his career earlier this season, said: ‘It's a little tough to put it into perspective this soon, but it's been a great summer for many reasons.

‘I've sort of put myself back into a position where I feel like I belong and I put in a ton of hard work.

‘Speaking just of this tournament, I don't think I've played necessarily my best tennis of the summer, but was in a position in the first three rounds of being the favourite. In the third round of a slam I haven't been in that situation many times, so it was nice to get through there.

‘But Novak played great today. I just didn't execute. I think he certainly had the advantage as far as playing on Arthur Ashe, I haven't played on that court in two years.

‘Man, is it different from playing on Louis Armstrong and Grandstand. There's hardly any wind outside and it's windy in there, really windy.

‘For him to play every match in there and sort of get used to that I think certainly helped him.’

Speaking about his win over Gasquet, 17th seed Monfils said: ‘It's not that easy to play when we are very good friends. He played very good today. I was a little better than him but I hope we will have more matches like this.

‘For me it's amazing to be in the quarter-finals. I love playing here, I feel comfortable and I hope I can win here one day maybe.’

Sweden's Robin Soderling also advanced to the quarter-finals with a four-set win over Spain's Albert Montanes, the fifth seed coming from a set down to win 4-6 6-3 6-2 6-3.

Soderling will face Roger Federer in the last eight, after the five-time champion defeated the Austrian left-hander 6-3 7-6 (7/4) 6-3 in the final match of the evening session on Arthur Ashe.