There is something about these marquee matches here at the Sony Ericsson Open that brings out the best in defending champion Serena Williams who today crushed world number 1 Justin Henin 6-2 6-0 in a mere 80 minutes of awe-inspiring tennis.

Last year Ms Williams, seeded 8, allowed Maria Sharapova just a single game on her way to the title where she beat Henin from two match points down, today she was again in a ruthless mode as she dominated the diminutive Belgian from start to finish, allowing her to hold serve just once.

Williams raced to a 3-0 lead, breaking Henin's opening service game to 30 as she struck the ball with the kind of authority that we haven't seen from her on a consistent level for some time.

Although Williams had points for 4-0, Henin held on grimly and then broke to bring herself back into the set. Just when you thought Henin was going to assert herself, she double faulted three times to hand the advantage back to her opponent.

Williams held and broke to love with the aid of a superb backhand crosscourt pass to clinch the opening set in 49 minutes.

The stunned crowd watched as Serena cleaned up in the second set, breaking the fragile Henin serve again and again as her returns got better and better. She hit two clean backhand return winners down the line and when she ran down a poorly executed drop shot and put it away for a winner to break for 4-0, the match was all but over.

Williams moved into the semi-finals on her third match point when the hapless Belgian double faulted for the fifth and final time.

Henin committed a total of 32 unforced errors to Williams' 15, and converted 1 out 4 break point chances compared to 6 out of 11 for her oppenent.

"I didn't make as many errors as I usually do, and, you know, I've been practising like a champ", Serena said. "Today I finally started playing a little bit the way I've been practising.

"I stayed positive no matter what happened; I think that was a pretty good turnaround."

Commenting on the fact that she has not beaten the world number 1 since the final here last year, proceeding to lose three consecutive Grand Slam quarterfinals against her, Serena said:

"It's kind of a letdown; I wish this was a Grand Slam more than anything. I'm going to try to do this at a Grand Slam and not only at this tournament.

"I'm always looking to be back to number 1, and I'm always looking to be on top. I think I wouldn't be in tennis if I didn't expect or believe that I could be. I'm just fighting every day and hoping to get there soon."

A shell-shocked Henin had anticipated a difficult match having beaten Serena on the last three occasions.

"I knew she was going to be really aggressive, attacking the ball, and I think she did what she had to do, and I didn't do what I had to do, so that makes a big difference in the end.

"Looks like she's moving better than last year, for sure. But I have a feeling that I really didn't do enough and take my opportunities. So many games I was leading and didn't take my chances; it was quite difficult.

"She was simply better than me, so I will have to keep working and one day I will get better."

Serena will next play Svetlana Kuznetsova who put out sister Venus with a solid performance, winning 6-4 6-4 in 87 minutes.

Andre Jones

Crandon Park

Key Biscayne