Emotions can run high and get the best of any of us in intense situations. Keeping them in check is part of the battle.
On a tennis court, when players lose their cool, heat-of-the-moment reactions have been known to lead to the most unfortunate of outcomes: a match default. On Sunday, world No. 1 Novak Djokovic became the center of a US Open disqualification sure to be talked about in the years to come.
Here are five defaults that are remembered for being on the wrong side of history.