No. 10 seed Caroline Wozniacki leads the head-to-head with No. 13 Sara Errani, 2-1, but the pair haven't played against each other in four years. The last time Errani recorded a win over Wozniacki was back in 2008, long before Errani established herself as a contender and even before Wozniacki reached the final here.
Fans inside Arthur Ashe Stadium can expect a match that will feature plenty of variety and long rallies. Both Wozniacki and Errani are counterpunchers, with the Dane possessing a bit more firepower and the Italian possessing slightly quicker speed around the court. Wozniacki will need to look to attack when the opportunity presents itself and step in on Errani's second serve, which typically clocks in at under 75 miles per hour.
In order to defeat Wozniacki, Errani will simply need to do what she does best: tirelessly run down every ball. In her fourth-round, three-set victory over Mirjana Lucic-Baroni, the Italian hit just four winners and committed just nine unforced errors in nearly two hours of play. The Dane is known for her mental prowess on the court and typically doesn't beat herself, so Errani will need to get a high percentage of first serves in and make things as relatively easy as possible for herself on the court.