TENNIS/French Open: When Roger Federer arrived in yesterday following his semi-final win over David Nalbandian - the Argentinian having retired with an abdominal injury - he was asked if he had considered the significance of winning tomorrow's French Open final.

He nodded and smiled: "Yes, I have." Perhaps reluctant to tempt fate by talking about a Grand Slam, that was all he would say.

With the second seed and reigning champion, Rafael Nadal, standing in his way, the 24-year-old's brevity was prudent. Federer has the 2005 Wimbledon and US Open titles as well as this year's Australian Open. Winning at Roland Garros would make him only the sixth man in history to have won all four titles. Importantly it would also keep alive the idea of a calendar-year Grand Slam as he heads toward Wimbledon, where he has won for the last three years.

Of the five - Andre Agassi, Don Budge, Roy Emerson, Rod Laver and Fred Perry - who have won all four titles, only Budge and Laver held all at the same time.

History aside, Federer must also be considering the attack of lethargy that had him struggling early in yesterday's match. He dropped his service twice to lose the first set 6-3 before recovering from 3-0 down in the second. The third-seeded Nalbandian called for a trainer when trailing 2-1 in the third set and again received treatment at 3-2 but had to quit after two more games.

It was the first retirement in the men's semi-finals at Roland Garros in the Open era.

Federer later admitted it took a few spectacular shots to give him "a tailwind" to get back into the game. At 3-1 down in the second set he chased a ball to the corner and almost blindly pirouetted to hit a brilliant cross-court winner.

"I thought I had to find a way to get into the match because I was not playing well and he was playing the way he is supposed to, not making errors," said Federer. "I just couldn't get the ball into play. I was shocked. So I knew something had to happen. That it took a shot like that is interesting. I can't pull those off on a consistent basis but they give you something extra. That's exactly what I needed."

Nalbandian had injured his abdomen during his quarter-final against Dmitri Davydenko but had felt fine stepping on court yesterday. But a similar problem had also caused him trouble at the Australian Open in January.

"I don't like to retire when I'm on court. But today was really bad," said Nalbandian. "I knew I had to be careful with the abs because of what happened in the match before. I mean I couldn't even serve."

It now makes for the final that everyone wanted as Nadal swept aside the Croatian fourth seed, Ivan Ljubicic, 6-4, 6-2, 7-6. The young Spaniard played the game he plays best, one of huge forehands and legs that allow him retrieve balls that seem lost.

Ljubicic had promised to make the points short by going for his shots. He felt the only way to win was to take risks. But quickly he learned that putting it into practice was difficult as Nadal swept to a 4-1 lead before taking the set.

He continued to dominate, easily taking the second set before settling the issue in a third-set tiebreak, taking it on his third match point. Afterwards Ljubicic complained about the amount of time Nadal took serving and was also furious over some of the calls.

Nadal goes into the final with good memories of his last meeting with the world number one as he recovered from the brink of defeat to capture the Rome Masters just before Roland Garros. Federer has beaten Nadal only once in five attempts.