Agnieszka Radwanska learned the hard way -- on international television at the 2011 Australian Open -- why banging your racquet on the court in frustration isn't just bad manners, but a possible ballboy injury waiting to happen:
And here's the video, with more of that priceless nonplussed expression:
Radwanska went on to win 6-4, 4-6, 7-5, which is sad for us, since she was playing Kimiko Date Krumm and one of our favorite things to do in this space is remind everybody that Kimiko Date Krumm is older than Michael Chang, but that video goes a long way towards making up for it.
HT: Our own Daily Forehand.