TENNIS: The last time the seeding committee called it perfectly right in predicting what players would make it to the semi-final stages, Mats Wilander then knocked it all on it's head by winning the 1985 tournament as the fourth seed.

Just 21 years ago now, Wilander beat the tournament favourite John McEnroe in the semi-final before defeating the second seed, Ivan Lendl, for the second of his three French Open titles. Until this year the top four players have never been able to stay in the draw until the Friday of the second week.

Whether that's good karma for Croatia's Ivan Ljubicic, who's seeded four, will be seen today and believe it when Lujbicic steps onto the baked-crushed red brick of Court Philippe Chatrier against Spain's Rafael Nadal, he will need every lucky charm, every burned candle, every votary as well as the karma to dislodge Nadal from his towering dominance of this tournament and clay-court tennis.

While Novak Djokovic determinedly espoused the frailties of Nadal's game before he retired in the third set with a back problem, there are few others who would agree with the young Serb that Nadal is there for the taking. After all the 20-year-old from Majorcan has dropped only two sets so far.

Last year when he won the trophy, he dropped three over the two weeks and with his win over Djokovic, took his unbeaten run on clay to 58 matches, which no other player in the Open era has been able to do.

Nadal did admit after his quarter-final that he lost concentration, which for everyone who has watched him carve his way through the two weeks, is as close as he has come to admitting a vulnerability.

"I'd been playing well until Djokovic started having trouble. That made me lose my concentration. I didn't really understand what was going on. In any case it's my fault," said Nadal.

That may go some way towards explaining why Djokovic said afterwards he believed Nadal was beatable and felt he had the match under control until his injury. That analysis was put to the Spaniard.

"Oh yes," said Nadal smiling. "If he says that, it's okay. Did he have the problem in the first game, no? Did I have the break, break all the time, no?"

Ljubicic was more grounded on the issue of his chances of beating Nadal. "He is the big favourite, over Roger (Federer) even," said Ljubicic. "But my ranking is good enough not to be intimidated by anyone."

Perhaps more quietly Federer and Nalbandian have been creeping through. The Swiss number one has dropped just one set while Nalbandian has been involved in a few battles along the way against a cast of characters that could belong in a spaghetti western. But the 24-year-old Argentinian has been here before and was runner-up in 2002 to Lleyton Hewitt at Wimbledon. Clay is also his surface.

It is Federer's view that Nalbandian has "a good back hand, fast, talented and can beat any player on this surface". But the Swiss player believes his game is in better shape this year and is more experienced on the surface. While Nalbandian possesses the determination and endurance to grind down opponents, he does not have the range of ability of the world number one.

"Thank God I realised in time what I needed to do," said Federer. "I've got my game into a position where I can play aggressive, I can play defence and I can play counter-attack. I have the option and that's very important in today's game."

Nalbandian's advance marks the second time in three years that he slips into the last four of the Parisian event. In 2004, he lost to eventual winner Gaston Gaudio.