“We are Antillais, we are soldiers, we have a mission to fulfil and we do it.” So said Gaël Monfils yesterday as France prepared to decorate its foremost tennis showcase in a manner that it accomplishes with such élan. What Jo-Wilfried Tsonga did for the people of the Democratic Republic of Congo at the Australian Open five months ago, so Monfils is achieving for Guadeloupe, an island race that bears allegiance to the homeland but so often feels like a distant, neglected cousin.

Monfils and Tsonga are the best of friends and what they have achieved for themselves and for French tennis in 2008 is immense. The latter is troubled by a knee injury, the former has one more step to take before he joins Tsonga as, at the least, a grand-slam singles finalist and there is a frisson of expectancy of something happening on Court Philippe Chatrier today that would be extraordinary.

For Monfils to reach the final at Roland Garros and avoid the banana skin that felled five other French players in the open era - Yannick Noah, Patrick Proisy and Henri Leconte have contested the final here, with Noah the lone victor - he will have to derail Roger Federer's attempt to win this title for the first time. Until this year's Australian Open, in which he lost to Novak Djokovic, the world No1 had not been defeated in a grand-slam semi-final in ten attempts.

Watching Monfils pick apart David Ferrer, the world No5 from Spain, in the quarter-finals on Wednesday - and the crowd's response to it - was a revelatory experience. It was not that long ago that he would walk on to court, dreadlocks tucked into a hoodie, with his iPod attached to each ear and golden shoes on his feet, the young man with the “look at me” attitude. It is different now. The 21-year-old stands tall and faces the world with no superfluous accoutrements.

Where once the French were comme ci comme ça about whether Monfils would make the grade and his overbearing attitude heightened indifference, there is now deep affection for him. After Monfils's victory over Ferrer, Christian Bimes, the president of the French federation and a man given to self-aggrandisement, burst into the studio where Monfils was being interviewed and gave the startled player a bear-hug. It was difficult to imagine Tim Phillips, the chairman of the All England Club, similarly fêting Andy Murray if he reached the last four at Wimbledon.

Nor would we be likely to see Murray cavorting across court in the manner of Soulja Boy, the American hip-hop artist, as Monfils has done after his past two victories. Some things look perfectly agreeable on clay but would not go down well on grass. Could it be that Federer will be dancing to Monfils's lyrical pace?

“I want to play my game,” the Frenchman said. “I wanted to be able to control the rallies against Ferrer, to let him think that he is leading, but I was still there. Sometimes I get screwed playing that game, but I knew I was feeling good on my legs and his ball was - well, it was good for me, I was there on all points. I'm very happy I'll play a semi-final on the central court, but this is not my last objective. I am hugely motivated.”

It was not that way a couple of years ago, when Thierry Champion, his coach, and Remi Barbarin, his physical trainer, worked themselves to a frazzle wondering how they could make Monfils appreciate that hard work was an essential requirement if he was to bring the best from his brilliance.

Last month, when Monfils was playing in the final of a Challenger tournament in Marrakesh, Morocco, Champion and Barbarin dared not think that they would be taking their seats in the players' annexe for semi-finals day in a grand-slam event.

“We had arguments, but we stuck together,” Monfils said. “To play Federer, this is like the Lakers versus Boston [in basketball's NBA Finals]. It's going to be a big match, probably the most important match in my career so far, but a semi-final is not the match. It's not the game seven yet.” The boy soldier from Guadeloupe marches on.