Years ago, I was preparing to serve in a singles match. At the same, exact moment, the wife and daughter of the opponent arrived to watch him play.
Just before my racket struck the ball, the wife called out to her husband. He turned his head as the ball zoomed over the net and bounced up into his (groin area).
The next few minutes seemed like hours as his family, myself and others watched, helplessly, while he writhed in pain.
Eventually, he continued play- but there was no contest.