Rain gave way to bedlam tonight at the U.S. Open.

Defending champion Serena Williams was charged with a point penalty on match point after yelling at a line judge for a calling a foot fault on her previous serve. The ruling gave Kim Clijsters a 6-4, 7-5 victory in their semifinal match, which had been delayed 32 hours because of rain.

After the line judge called the foot fault with Serena serving at 5-6, 15-30 in the second set, the youngest Williams sister intimidatingly stared her down before screaming at the official with a jabbed finger. After a few seconds, Serena turned back around to serve, thought better of it and resumed the badgering. The chair umpire then called over the line judge to ask what Serena had said, rules officials were summoned, a brief summit occurred at the net and it was determined that Serena would be assessed a point penalty for a conduct violation. The point gave Clijsters the match. 

The initial foot fault that began the fireworks was a terrible call. It was unconscionable. It cannot be made at the end of any match, let alone in the semifinals of the U.S. Open. This isn't because a foot fault is a ridiculous call at that juncture (even though it is). It's because it wasn't a foot fault. The replays show that Serena's foot was behind the line when she served. You could make the argument that it was close but not close enough to make the call.

That being said, it's no excuse for Serena to berate an official. Wrong as the official may have been, there's a line that to be crossed and Serena did it pretty early on in her diatribe by saying, "I'm going to shove this ball down your f------ throat".

It got worse from there. There were multiple profanities, more threats and a lot of pointing. Serena was soon defending herself against accusations that she had threatened to kill the lines judge. Even John McEnroe said it was a bit much.

The explosive end is sure to obscure the fact that Serena probably would have lost the match without the foot fault. Clijsters was playing great and Serena couldn't win a point on her second serve. The end was coming, Serena's outburst merely hastened its arrival. Maybe that was the point.