The number one women's tennis player in the world, Caroline Wozniacki, played a Swedish Open match on Tuesday against a French player named Alizé Cornet.

And right before Wozniacki was about to serve for match point, someone's cell phone went off. So she stood there waiting for the person to mute it... until Cornet realized it was HER phone.

And when she ran over to her bag to turn it off, she got a big laugh from the crowd and a big smile from Wozniacki.  Wozniacki ended up losing the set but won the match.