Kim Clijsters should have listened to what Venus Williams had been saying earlier Thursday after her 6-3, 6-4 win over Marion Bartoli. Venus was asked how the game had changed since she first appeared at Key Biscayne in 1994.

"Everybody thinks they can win now," she said. "When you got up 3-0, the match was over and that's not the case anymore. Once you're 3-0, you have to be careful it's not three all in a couple of moments."

How perceptive was that? Clijsters led Justine Henin 6-2, 3-0 and in a couple of moments it was three all. In the end Kim won this battle of the Belgians in the third set tiebreak in the semifinals of the Sony Ericsson Open, just as she had when they met in the Brisbane final in January but, dear me, did she make a meal of it.

It was a match of high intensity and incredible excitement as the 6-2, 6-7, 7-6 score suggests, but both these former world No. 1's can play at a higher level than this. Perhaps we are asking too much of two players who took a long time away from the game. It is a tougher world to which they have returned and, even if it all came up roses for Clijsters at the U.S. Open last September, the flowers can wilt.

Clijsters, who suffered a bad defeat early in the tournament at Indian Wells, has often struggled for consistency, even before leaving the game for marriage and motherhood. She is prone to suffer from that Evonne Goolagong tendancy to "go walk about," as the Australians say, and the way she lost focus at 3-0 up was astonishing. In the fifth game, she handed Justine a passage back into the match by double faulting three times in five points.

But with her wonderful backhand struggling to find its zip and depth, Henin seemed incapable of making full use of the opportunities being handed her and a second break of serve, which arrived after Kim had slapped a forehand and then a backhand way out of court, was not enough. She failed to serve out for the set, double faulting twice herself, and needed the breaker, which she took 7-3, to get herself on level terms.

Holding serve became a lottery in the third -- there were six breaks in eight games -- and, in the end, another tiebreak seemed the only logical way to end an unfathomable contest. Clijsters got herself in position to close it out with a couple of huge forehand winners and was serving for the match at six points to three.

But that was all too easy, of course. More errors on both flanks from Kim threw away both match points on her serve. And the third was squandered when she put a routine service return into the net.

A volley which seemed to fly off the frame got Clisjters back to match point in fortuitous fashion, and with that 6-2, 3-0 lead a distant memory, she finally nailed victory with a forehand winner.

"It was disappointing, of course," said a philosophical Justine afterwards. "It was not a great match. I've played better and she was the one who really went for her opportunities."

Clijsters knows she has to seize those opportunities by being aggressive no matter how many mistakes she makes.

"Obviously I tried not to let it effect me (losing her lead) and really tried to stay focused," said Clijsters. "I tried to move in when she was slicing -- just step in and don't wait for it. I tried to be really aggressive and I think that's the game I have to play against whoever I am playing."

Venus will be waiting for her in the final -- waiting for those moments when a 3-0 lead can disappear.

Earlier Thursday, Robin Soderling underlined his increase in stature since becoming such an unlikely finalist at the French Open last year by dismissing Russia's worthy but outgunned Mikhail Youzhny 6-1, 6-4. The tall Swede has always had the firepower, but in the last twelve months he has learned how and where to direct it. There will be plenty coming from the other side of the net in the semifinal when he faces the equally powerful Czech Tomas Berdych. It should be a good battle.