With the Labor Day weekend comes the midpoint of the U. S. Open. And as play made the turn for the home stretch, there were compelling matches once again at the Billie Jean King Tennis Center on Sunday.

Wozniacki Outduels Sharapova

Tenth seed Caroline Wozniacki mixed her counterpunching tendencies with some key attacking groundstrokes to defeat fifth seed Maria Sharapova 6-4 2-6 6-2 on Sunday.

In one of the better matches of the tournament, Wozniacki found the ability to adjust during the contest and overcame a patented Sharapova comeback. In the first set, the Dane operated in her comfort zone, baiting Sharapova into 21 unforced errors while limiting her errors. Yet she took her stabs at opportune times and found success on the attack when needed. She earned two breaks of service, enough to give her the first set.

However, in what has been typical of the Russian, Sharapova picked up her intensity in the second, battering Wozniacki with her groundstroke assault as the 24-year-old was forced on the defensive. It appeared that the match had swayed in the higher seed’s favor as the pair advanced into the third set even at one set apiece.

But it was Wozniacki adjusting in the third set, picking up her attack while appearing to harness more energy than the 27-year-old. With an assortment of deep groundstrokes, she moved Sharapova around the court, keeping the pressure on the Russian. The tactic limited Sharapova, who uncharacteristically fired just four winners in the set. And in what was a turning point, Wozniacki exhibited tremendous defense in a break point, running down big strikes from Sharapova's racket. However, when an errant shot by her opponent found the net, the Dane had broken to gain a 3-1 advantage. Wozniacki played to the New York crowd, much to their delight. She would take five of the last six games in the set on her way to a quarterfinal appearance for the first time in her last 10 Grand Slams.

When questioned about her defense during the match, Wozniacki replied, “I never give up. Even when it looks impossible for me to get to a ball, I'm still gonna try.”

Sharapova gave credit to Wozniacki. “I think she's moving extremely well. She’s always been fit, but there is a little bit more on her defense shots. It's not just balls up in the air. She's doing a little bit more with them. But she did that really well today.”

Errani Advances

No. 13 seed Sara Errani took to Ashe Stadium on Sunday following an emotional win against Venus Williams on Friday. She had to come back to earth in her meeting with Marjana Lucic-Baroni, but after a hard fought effort by the 32-year-old, Errani advanced to the quarterfinals 6-3 2-6 6-0.

Lucic-Baroni has been a story of inspiration with her comeback to tennis after missing several years, but it was a shaky start against Errani for the veteran who overpowered second seed Simona Halep in the third round. Her aggressive style led to a number of early unforced errors while Errani steadied the ship, jumping out to a 3-0 lead. Regardless, the Croatian continued her aggressive play and finally scratched the surface with a break of Errani's serve. But the counterpunching Italian would go on to take the first set at 6-3 despite just a single winner.

Between sets, Lucic-Baroni called for a trainer to address her right leg and ultimately used a medical timeout. But as play resumed, she was able to pinpoint her aggression by attacking Errani's service games. And in the second set, her attacking style broke the Italian twice, allowing her to coast and take the set.

However, Errani quickly regained control in the third set, and the errors that derailed Lucic-Baroni in the first reared their head again in the third. The combination led to a bagel set for the No. 13 seed, who advanced to the quarterfinals. 

Peng Defeats Another Seed

For the third straight match, Peng Shuai defeated a seeded player. After defeating Agniezka Radwanska and Roberta Vinci, she defeated 14th-seeded Lucie Safarova in the fourth round 6-3 6-4.

Peng raced out to an early 3-0 lead in the first set by doing what she does best, playing precise, clean tennis. An early break was all Peng would need, and after a set in which she gave away just three unforced errors, she closed it out with momentum.

Much like the first set, Peng grabbed an early break of service in the second. After consolidating that break, the set became a carbon copy of the first set. The native of China continued to play consistent tennis by protecting her serve while only giving away four unforced errors. She served out the set and the match to advance to the quarterfinals.

Teenager Derails Jankovic

Veteran Jelena Jankovic met 17-year-old Belinda Bencic in Ashe Stadium, and it was the teen advancing 7-6 6-3. Both players struggled holding serve early with three consecutive breaks of service to start the first set. However, as the set progressed, each improved their service holds, but neither competitor played up to their capabilities elsewhere. Nevertheless, play progressed to a tiebreak to determine the set, where the quality improved and the youngster got the better of the veteran at 8-6. 

In the second set, Bencic gained confidence and began to play like a veteran with a poise beyond her years. Attacking Jankovic's serve, she broke the Serb three times, including the decisive game, with Jankovic serving at 3-5. With the crowd behind her, she claimed the biggest win of her career.