Sixth-seeded Sloane Stephens shrieked in disgust after watching her baseline shot hit the net for an unforced error. Down 5–1 at the change in a first-set tiebreak, Stephens had mounted a furious comeback to close within a point of fourth-seeded Caroline Wozniacki, 5–4. Yet that error dropped Stephens into a 6–4 hole from which she was unable to recover, losing the tiebreak 8–6.

After the closely contested first set ended, the frustration only continued to mount for the American favored by much of the sparsely filled stadium at the Cullman-Heyman Tennis Center. Wozniacki defeated Stephens 7–6 (8–6), 6–2 to advance to the semifinals of the New Haven Open at Yale Thursday night, concluding the day’s singles action.

“I thought I played pretty well this whole match,” Wozniacki said, addressing the crowd from the court after her victory.

The night provided more than a couple of scares to the New Haven Open veteran Wozniacki. After the competitors held serve for the match’s first four games, Stephens broke Wozniacki to take a 3–2 lead in the first set. The American then fought off two consecutive break points in the next game to force deuce, followed by two more winning points to hold serve. Stephens would break Wozniacki once more in the set.

The Dane won two games off serve in the set, however, leading to the tiebreak that she ended up winning.

Wozniacki, who won the Open four consecutive times between 2008 and 2011, acknowledged her success at the event after her match.

“I wish every tournament could be here,” she said, receiving a warm round of applause from those in attendance.

Despite her first-set effort, Stephens seemed to lose momentum in the second set. She mustered only one point in her second service game of the set, falling behind 1–2, and managed to win only one game in the set.

The match featured six review requests by the players, but only the final one reversed an official’s call. With Stephens serving behind 2–4 in the second set, Wozniacki managed to gain advantage out of deuce. Wozniacki’s shot on the next point was ruled long, but the player challenged the call and won the point on review. The reversal brought the second set score to 2–5, a margin that proved insurmountable to Stephens.

Stephens, the rising star still in search of her first tournament title, remained upbeat despite the loss.

“I played a lot of matches in the last couple of weeks and feel good about my game,” she said.

The first game of the match also featured the third-longest rally at the stadium court during the year’s tournament, a 23-shot point that Wozniacki won. The length of the match was 1:35.

Third-seeded Petra Kvitova, Simona Helep and Klara Zakopalova also advanced to the quarterfinals with wins over Anastasia Pavlyuchenkova, Ekaterina Makarova and Elena Vesnina, respectively. Wozniacki will take on Helep in the semifinals tomorrow, while Kvitova squares off against Zakopalova on the other side of the bracket.