Federer cautious of Del Potro

The Swiss cannot afford to relax as he prepares for what is, remarkably, his 20th successive semi-final in the world's four major tournaments.

At Roland Garros, Roger Federer is two victories away from equalling Pete Sampras' record of 14 grand slam titles.

Roger Federer will be delighted that the three men who have fought hardest with him at the top of the world rankings over the last two years - Rafael Nadal, Andy Murray and Novak Djokovic - are no longer posing a threat to his elusive dream of a first French Open title and a coveted career Grand Slam.

The Swiss cannot afford to relax, though, as he prepares for what is, remarkably, his 20th successive semi-final in the world's four major tournaments because the man who is closest to breaking into that elite top four is looming large and menacing at Roland Garros. Juan Martin Del Potro has made rapid and impressive improvements to his status in the game since leaving Wimbledon as a second-round loser last July and embarking on a run of four successive titles - a sequence of 23 wins which was ended by Murray in the quarter-finals of the US Open.

The fearsome Argentine has the capabilities to become a giant of the game in every respect and his 6ft 6in frame is a clear and present danger to the stylish Swiss who is now the obvious crowd favourite in Paris after defeating the last remaining home survivor, Gael Monfils, in the quarter-finals. Federer, who confesses to being extremely nervous as a lifetime's ambition - he is also on the brink of equalling Pete Sampras's record haul of 14 grand slam titles - comes within two matches of fruition, is sensibly not putting too much relevance on his impeccable previous record against Del Potro.

Five times the pair have met and on each occasion the Swiss has gone through in straight sets, most emphatically in the quarter-finals of this year's Australian Open when a 6-3, 6-0, 6-0 verdict was returned. Del Potro, 20, who more recently came off second best in the Madrid semi-finals, reckons he has learned from those painful lessons and promises to continue the Roland Garros approach which has seen him reach his first grand slam semi-final for the concession of a solitary set - to Jo-Wilfried Tsonga in the fourth round.

"When I play Roger, I have no choice, so I have to play my game," said the fifth-seeded Del Potro after his thrashing of the Spanish clay court specialist Tommy Rodrebo in Wednesday night's quarter- final. "Otherwise I'll never achieve anything. "He [Federer] does everything perfectly. His game is much of a problem to me, and this is why I've never won when I played him." Federer is cautiously optimistic about going through to meet either Sweden's Robin Soderling or Fernando Gonzalez, of Chile, in Sunday's final.

"I expect a very difficult match against Juan Martin," said the world No 2. "I have a lot of respect for him. Yeah, I have a good record against him, but it doesn't mean a thing right now because it's too big of a match, too dangerous, and he's playing too well to underestimate him." The two other semi-finalists have been more evenly matched in previous meetings with Gonzalez, a quarter-final conqueror of Murray, holding a 4-3 advantage over Soderling who shook the tennis world by eliminating the four-time champion Nadal in Sunday's fourth round.

"I have not had a very easy draw," said Soderling with massive understatement after adding the awkward Russian Nikolay Davydenko to his list of scalps, which includes David Ferrer. It will not get any easier for the Swede against Gonzalez who outgunned Murray in their quarter- final and is playing with a swagger to suggest that he is another with the potential to be a surprise champion here. [e-mail]