Henin cast as the outside courtier

Directly translated into her native French, she would be known as the "cheval sombre". In pure tennis terms, though, Belgium's newest tennis sensation, Justine Henin, is being labelled more simply as "l'outsider". The highly rated 19-year old is seen by many, including John McEnroe, as the dark horse of this year's event, although her progress so far has been more like that of a smart cat.

Henin has tip-toed her way into the fourth round, attracting little publicity and keeping her head firmly down. But don't be fooled. Her comeback against Kristie Boogert, when she was a set and 4-1 down, before winning in three, showed her mettle. And her straight-sets victory against the experienced American Lisa Raymond, a grass-court specialist, proved Henin is a force to be reckoned with. "That was a good result for me," she admitted after her win late on Friday evening. "I think I have been improving steadily since the beginning of the tournament and I'm approaching my best tennis."

Henin's timing could not be better. The top half of the women's draw is the more open by far, particularly since Martina Hingis' first-round exit, and Henin has a relatively easy passage to the semi-finals, where she would probably meet either Jennifer Capriati or Serena Williams. Henin, though, has more immediate targets.

If she can defeat Anke Huber, who is still only 26 but playing her 11th Wimbledon, she will become the first Belgian woman to reach the quarter-finals of Wimbledon. "I'm not thinking about that," she said. "All I know is that when you make it to the second week, it's a new tournament which is starting. There is a totally different type of pressure on you, but I don't mind that. In a sense, it keeps you more focused."

Henin has burst on to the scene in the last 12 months. She went out of Wimbledon in the first round last year and suffered a series of nagging injuries, before making a full recovery and then reaching the semi-finals of the French Open last month. She lost there to her fellow countrywoman, Kim Clijsters, but Henin believes that the experience she gained that day is immeasurable. "It means that if I had the possibility next time, maybe I would have a very different reaction."

One action which Henin can be proud of is her back-hand. Not only a weapon of lass destruction, it is also a joy to watch. Indeed, just as the ball approaches her on the left-hand side, Henin will quickly alter her grip, before unleashing a perfect-looking stroke. Most significantly, hers is a one-handed back-hand, a rarity in the women's game these days.

In many ways, Henin is everything you wouldn't expect. A Belgian tennis star, for starters. "I know, I know," she said. "Don't ask me why we are suddenly doing well because I don't have a clue." She is also, at 5ft 5in, short by modern standards, yet that does not stop her from belting the ball. "People still know relatively little about me," she said, "so perhaps that is why I'm now suddenly grabbing their attention.

"Maybe I am the dark horse. There are always surprise packages at a Grand Slam and there's no reason why I can't be the surprise of this year's Wimbledon."