Caroline Wozniacki defeated Maria Sharapova in three sets at the US Open's fourth round on Sunday, 6-2, 4-6, 6-2. Wozniacki has never won a Grand Slam title, and has not advanced to the quarterfinal of a major since the Australian Open in 2012. In 2009, she lost in the final of the US Open.

As the 10th seed, Wozniacki's win was considered an upset over 5th seeded Sharapova. In the quarterfinal, Wozniacki will face Sara Errani. 

Wozniacki showed increasing emotion through the match, and had one rally in particular in which she won on a Sharapova error. Overall, Wozniacki's win was impressive, to say the very least.