I watched that match. Congratulations to Clijsters for an excellent victory, I'm sure all of Belgium is buzzing about this one.
Clijsters began the match very well, crossing up Serena and returning her most powerful serves with some ease. The first set went back and forth until Kim made a nice comeback at the end, winning the final 3 games. I think Serena kind of gave up in the second set, she looked a bit exhausted.
I hope this marks the beginning of a new rivalry, it's genuinely needed in women's tennis at the moment.