Murray worries Federer ahead of semi-final

TENNIS world No2 Roger Federer admits Britain’s Andy Murray has blossomed into a far more dangerous opponent as they prepare to face off in tomorrow’s Australian Open semi-finals.

Federer dropped his first sets of the tournament in beating seventh seed Jo-Wilfried Tsonga yesterday, after Murray strolled past another Frenchman, Jeremy Chardy, in straight sets.

The Swiss maestro beat Murray in last year’s Wimbledon final, but the Scot took revenge in the London 2012 gold medal match and has since claimed his first grand slam, at the US Open.

“He has changed his game around a bit. He’s playing more offensive. I’m looking forward to it,” said Federer, who beat Tsonga 7-6 (7-4), 4-6, 7-6 (7-4), 3-6, 6-3.

“How offensive can you play when the ball is coming flat and hard into the middle? You also have to know when to back off. He’s very clever at all these things. But I think it’s especially on the return that you see the biggest change in his game.”

Murray is yet to drop a set in Melbourne this year after sweeping aside unseeded Chardy 6-4, 6-1, 6-2 in less than two hours.

“I think you have to trust yourself that when you’re tested, you’re going to play better tennis,” he said. “But I’ve done a good job so far in this tournament. I can’t be disappointed with where my game’s at.”

Women’s favourite Serena Williams suffered a shock quarter-final defeat to fellow American Sloane Stephens, 19, after enduring back spasms. Stephens, who downed Britain’s Laura Robson in round three, beat the 15-time grand slam winner 3-6, 7-5, 6-4 to set up a semi-final with top seed Victoria Azarenka.

Williams, who needed treatment in the second set, said: “I’m almost relieved that it’s over because there’s only so much I felt I could do.”