Even if you put it mildly, Roger Federer was blown away by Rafael Nadal in the French Open final. It was the world number one's worst defeat in 173 Grand Slam matches. It was the most one-sided men's final in a Grand Slam since John McEnroe hammered Jimmy Connors at Wimbledon in 1984.

Losing to Nadal in the French Open wasn't so surprising; Federer had lost to the Spaniard in each of the previous three editions — in the semi-finals in 2005 and in the finals in the next two years. But it was disconcerting to see Federer winning just four games.

It has been disconcerting to see him all of this year so far. The normally immaculate game seems to have become less so and his armoury appears to have developed chinks. His aura of invincibility has been dented by lesser-known opponents like Mardy Fish and Radek Stepanek.

That would have been all right if he had continued beating the top players (champions often suffer surprising losses to unheralded rivals). But he lost his Australian Open title to Djokovic, which was his first Grand Slam semi-final defeat after playing 10 consecutive major finals. And Nadal continues to be a nemesis.

The Spaniard now leads their head-to-head series 11-6 and has won nine of their 10 matches on clay. Federer's only title this year came in a minor clay-court event. In the French final, he committed more than twice as many unforced errors as winners.

Thus, for the first time in years, Federer looks vulnerable going into Wimbledon, where he has beaten Nadal in the last two finals, with the last year's going to five tight sets.

The bigger point is that, going by this year's show, 2007 may have been Federer's peak. He almost certainly will win more majors and overtake Pete Sampras' record of 14, but may struggle to regain his aura of dominance.

Still, there is little need to feel sad for Federer. He has had an outstanding career and dominated the game like few others have. Even if he does not win the French, he will always be in contention to be dubbed the best ever.

In the modern era, only Andre Agassi managed to win all four majors. Sampras failed in France, as did McEnroe, who blew a two-set, 4-2 lead in the 1984 final. Borg never won the US Open despite playing four finals.

Sampras and McEnroe, for all their skill, never really dominated on clay. Borg was always off-colour on hard courts. Federer can legitimately claim to be the second best on clay in his era, next only to Nadal, who is probably the best ever on that surface.