The 45th-ranked 23-year-old was the favorite to beat 101st-ranked Mattek-Sands, but she fell behind 5-0 in the first set. In a rage she slammed her racket into a chair and then repeatedly on the court, bending it. Hearing the crowd's reaction, she raised her arms and stood, giving the racket one final smash.
Vandeweghe had a sense of humor about the ordeal. When a podiatrist made a joke about her being angry because she was hungry -- a play on Snickers' slogan -- she said it was a good joke.
Mattek-Sands will go on to play Serena Williams in the third round.
The Associated Press contributed to this report.