Tennis star Serena Williams has been fined $10,500 for her outburst at the semi-finals by the U.S. Open officials.

According to the Associated Press, Serena's outburst was directed towards a line judge.

She was called for a foot fault on Saturday night in her U.S. Open semifinal loss to Kim Clijsters.

Below is the video of her outburst:

Serena Williams outburst video 1:

Serena Williams outburst video 2: