Awesome Murray storms into world top five

Andy Murray had every reason to flex his muscles again today after climbing into the world's top five for the first time.

Murray stormed into the quarter-finals of the US Open here in New York by destroying close friend Stanislas Wawrinka 6-1, 6-3, 6-3 under the Flushing Meadows floodlights.

It means the British No1 will now face a grudge match against Juan Martin Del Potro, the young Argentinian who aimed a ball at Murray and complained about courtside support from his mother, Judy, when they met in Rome earlier this year.

Del Potro eventually retired from that match with a back injury but there is lingering resentment over the incident and it promises to turn the quarter-final into a "must-see" battle. However, Murray's mother is not here, which removes one potential flashpoint.

Murray said he had told Del Potro at the time to "watch his mouth" and added: "My mother is one of the nicest ladies you're ever going to meet. He can say whatever he wants about me, but when you start talking about someone's family I think it's natural not to take it too well." Having been warned for swearing in Rome - which he denied - Murray was unhappy that Fergus Murphy, the umpire, took no action against Del Potro.

Murray admitted today he is not on friendly terms with his next opponent and has not spoken to him since their confrontation.