Weather has been a big issue at this year's US Open in New York. The heat and humidity during the day and the gusty wind at night have impacted matches immensely, and none more hilariously than in the moments before Caroline Wozniacki clinched the match point to advance to the women's semifinals on Tuesday night. A determined ballgirl raced across the court and snatched a flying plastic bag out of the air, triumphantly. Garbage, towels, and pretty much anything else has been blowing around at the night matches, onto the court and into play at times. Not on this ball girl's watch, though.

Wozniacki defeated Sara Errani in straight sets 6-0, 6-1.