No matter how loudly Rafael Nadal dismisses comparisons with the great Bjorn Borg, he cannot escape the fact he is on course to equal the Swede's remarkable four-in-a-row French Open titles at Roland Garros.

Nadal thundered into a semi-final showdown with Australian Open champion Novak Djokovic on Friday with a ruthless 6-1, 6-1, 6-1 humiliation of Andy Murray's conqueror, Nicolas Almagro.

While Borg played in a different era - wooden rackets and a slower pace of tennis life - he remains the clay-court icon everyone else is measured against in Paris.

But Nadal said: "Comparing myself to Borg, how could I dare do that? He was one of the top three players in all the history of tennis.

"Everybody's talking about Borg as if he was somebody from another planet. But Borg was Borg. He was not any different. When he was walking on the court, everybody felt he would never lose."

Many feel the same about Nadal, who holds a 7-3 career win advantage over Djokovic. Nadal has won all four of their matches on clay, although Djokovic is improving all the time. Unfortunately for the 21-year-old Serb, so is Nadal.

The Spaniard celebrated his 22nd birthday by hammering compatriot Almagro. Nadal's victory was the most one-sided quarter-final in the open era and he has conceded only 25 games getting into the last four, another best for this particular Grand Slam.

Even so, Nadal insists his name isn't already on the trophy. "There is no such thing as a pre-written script before the tournament starts," he said. "Anything can happen."

Almagro was left with only praise for the impressive Nadal. He said: "Just congratulate him, wish him a happy birthday and wish him all the best for the rest of this tournament. Quite clearly we'll have a champion for many years here in Roland Garros."

Djokovic had more trouble in subduing Ernests Gulbis, with whom he used to practise when they were barely into their teens. However, he has moved ahead of the Latvian in the past couple of years and had the big- match experience to go through 7-5, 7-6, 7-5.

Djokovic recognises Nadal has stepped up his game and said: "He has improved the serve a lot and he's going for some shots much more. He combines that with his great physical strength and then patience, and it's impressive on this surface. But I don't want to go out in the semis - I want to win.

"I have a good chance. Of course, he's the favourite but only with a positive attitude can I get the positive outcome."

The all-Serb women's semi-final tennis fans wanted was created by Ana Ivanovic and Jelena Jankovic, both of whom came through their matches yesterday with ease.

Ivanovic is the favourite after beating 10th seed Patty Schnyder 6-3, 6-2. She said: "Hopefully, I can win the tournament and there are very tough opponents still here. Yes, I beat them before but they also beat me. So I have to go out there and play each match like it's a final."

Jankovic beat unseeded Carla Suarez Navarro 6-3, 6-2 with a bandage on her injured right arm displaying the message "I love Paris" written on it. She flew back home to Serbia for treatment and then returned 24 hours before the match.

The world No3 said: "After the match with Agnieszka Radwanska [in the fourth round], I had a lot of problems with my arm. I flew by private plane that night and I had treatment.

"I had another treatment in the morning and then f lew back. Otherwise, I don't think I'd be able to play because I was in a lot of pain.

"Two Serb players! I think we're going to be dominating this tennis world soon. It's great for Serbian tennis and for the whole world to have new faces, new players and great rivalries."