Imperious Nadal in great form as he looks to pile misery on fallen Federer

A fascinating US Open went into its second week yesterday with five of the top eight seeds in both singles events still involved. Rafael Nadal has looked every inch a world No 1 at the top of the men's rankings but the top spot in the women's game has become a hot potato in recent weeks and remains up for grabs at Flushing Meadows. With Nadal continuing in the form that has brought him two grand slam titles and an Olympic gold medal in the last three months, the Spaniard is on course to add more misery to the man he has deposed as world leader, Roger Federer.

Nadal, who thrashed Federer on the clay of Roland Garros in June and edged out the Swiss in a grass court classic at Wimbledon in July, is brimming with confidence as he seeks to bring to an end Federer's four-year reign as champion on the hard courts of New York. Neither man has dropped a set yet, with Federer possibly showing even better form in despatching his first three opponents than his nemesis.

Novak Djokovic, the young Serbian who is hoping to overtake Federer and ultimately catch Nadal, has looked less impressive so far. The Australian Open champion expended four hours of valuable energy in overcoming Croatia's Marin Cilic 6-7, 7-5, 6-4, 7-6 in a fierce battle of the Balkans. That exhausting victory earned Djokovic, the runner-up to Federer here last year, a tougher fourth round encounter against the 15th-seeded Spaniard Tommy Robredo than Nadal and Federer are likely to face against Sam Querrey, of the US, and Igor Andreev, from Russia, respectively.

Whatever happens in the second week it has been a worthwhile event for Britain's Andy Murray, who traded blow for blow with Djokovic as they climbed the rankings together as keen rivals in their junior days, but has fallen behind his Serbian friend over the last year, partly because of a serious wrist injury. Murray, who won one of the key warm-up tournaments in Cincinnati is closing fast on the two players immediately above him, David Ferrer and Nikolay Davydenko, both of whom departed before the end of the first week at Flushing Meadows. Murray, already at a career high of sixth in the world, could before long be up to the dizzy heights of fourth. [e-mail]