Djokovic and Nadal hunt down Federer

Roger Federer will face Novak Djokovic in the Australian Open semi-finals (AP)

Roger Federer must feel like Butch Cassidy and the Sundance Kid, who kept peering through their binoculars as the bounty-hunters closed in on them and muttered in disbelief and apprehension: "Who are those guys?"

For the planet's best tennis player those guys are Rafael Nadal and Novak Djokovic. A 7-5, 7-6, 6-4 victory over James Blake here last night ensured that Federer will still be world No 1 come the end of the Australian Open, but the pursuit of the 26-year-old Swiss by the 21-year-old Spaniard and the 20-year-old Serb has been relentless.

Nadal, who is meeting France's Jo-Wilfried Tsonga in the semi-finals here today, has still not won a Grand Slam tournament other than the French Open, but his consistency elsewhere has put him within touching distance of Federer. If the champion had lost to Blake, Nadal would have ended his 208-week reign as world No 1 with victory here on Sunday.

Djokovic, who took his place in the last four with a 6-0, 6-3, 7-5 victory over David Ferrer, has rapidly turned what had been a two-way battle for global supremacy into a three-cornered fight. Nadal, the world No 2 since July 2005, is the only one of the three who has not reached the semi-finals of the last four Grand Slam events, having lost in the fourth round of the US Open. "I always think when the top three or four guys play against each other it's entertaining for us," Federer said. "I think it's great that Rafa made it through, along with Novak. It's good for tennis."

The superiority of the leading lights was underlined by the quarter-final victories of Djokovic and Federer. Ferrer is one of the game's most improved players, but the speedy Spaniard was never in contention. The only time Djokovic looked rattled was when he complained about a baby crying in the crowd. The umpire responded with a public appeal: "Please give our crying friend a bottle."

Djokovic, who will attempt to stop Federer's progress to his 11th successive Grand Slam final tomorrow, broke into the world's top 10 only nine months ago, but by the time the new rankings list is released on Monday, his points total as world No 3 could be more than double that of Ferrer, who is set to climb to No 4. Federer, meanwhile, rarely looked in danger of failing to complete his eighth win in eight matches against Blake, despite having his serve broken three times. The American played some fine tennis, particularly in a wonderful second set tie-break, but Federer's all-round excellence took him to victory in just over two hours.

Djokovic has already taken Federer's scalp once – in winning the Montreal Masters in August he became the first man for 13 years to beat the world's top three players (Federer, Nadal and Andy Roddick) – but lost in straight sets when they last met, in the US Open final four months ago, after failing to convert seven set points in losing two successive tie-breaks.

"I felt after the win against Roger in Montreal that I had big chances in the [US Open] final but didn't use them," Djokovic said. "Now I look at things in a different way. Every time I play Roger, or any of the best players in the world, I learn something new. People were saying that the year after your breakthrough year is the most difficult, but I'm feeling really good at the moment, physically and mentally."

The extraordinary success story of Serbian tennis continued in the women's quarter-finals, with Ana Ivanovic beating Venus Williams, who knocked her out of Wimbledon and the US Open last year but was clearly affected by heavy strapping to her left thigh.

Ivanovic won an error-strewn match 7-6, 6-4, 24 hours after her compatriot, Jelena Jankovic, had ousted Serena Williams. Serbia has repeated the feat it achieved at Roland Garros last year of supplying three of the eight singles semi-finalists. The other five places have also been filled by Europeans, with all four women's semi-finalists coming from behind the former Iron Curtain. In today's semi-finals Ivanovic was playing Slovakia's Daniela Hantuchova, a 6-2, 6-2 winner over Poland's Agnieszka Radwanska, while Jankovic was taking on Maria Sharapova.

The Women's Tennis Association made inquiries yesterday about a controversial throat-cutting gesture that Sharapova's father, Yuri, had made immediately after her quarter-final victory over Justine Henin. Larry Scott, chief executive of the WTA, said: "I have spoken to Maria's camp and I am satisfied that this was an inside joke between Maria and her father related to his sweatshirt."