For years, one of the main critiques of the Women’s Tennis Association has been the lack of consistency among its top players. But at the New Haven Open at Yale, one player has ruled the Elm City for four years running: Caroline Wozniacki of Denmark.

The world’s No. 8, Wozniacki is undefeated in 20 matches in New Haven. But despite that success, she is seeded third this year due to middling performances earlier in the season that may have signaled an end to her dominance in the Elm City.

Wozniacki is again through to the semifinals, but after she sustained an injury to her right knee in her quarterfinal victory, she will have to fight for her place in the final, just a week before the U.S. Open begins. Wozniacki will have to choose Friday whether to step onto the court and compete for her fifth consecutive New Haven Open or to conserve her strength for the season’s final major tournament.

After taking the first set of her quarterfinal match 6–2, Wozniacki injured her knee while hitting a backhand in the first game of the second set. But Dominika Cibulkova, the tournament’s No. 6 seed, was unable to take advantage of Wozniacki’s injury, and Wozniacki cruised to victory, taking the second set 6-1.

Elsewhere in the bracket, No. 1 seed and world No. 2 Agnieszka Radwanska fell in the first round to Belarusian qualifier Olga Govortsova. Already down 6–0, 2–1, Radwanska cited a shoulder injury and opted to retire early in the second set.

All three other semifinalists pose real threats to Wozniacki’s dominance, should the Dane decide to continue: No. 2 seed Petra Kvitova, the Wimbledon champion of 2011; No. 7 seed Maria Kirilenko, recently buoyed by a fourth-place finish at the London Olympics; and world No. 10 Sara Errani, an Italian who was the runner-up to Maria Sharapova at the French Open earlier this year. Kirilenko and Wozniacki will face off in one semifinal, and Kvitova and Errani in the other.

Yale’s role in the New Haven Open is both geographical and financial, said Jeff Watson, a tournament spokesman. The tournament is played at the Connecticut Tennis Center at Yale, adjacent to the Yale Bowl, and Yale is one of the four cornerstone sponsors of the event. The University decided to provide financing for the tournament following the fall 2009 withdrawl of Pilot Pen, its previous primary sponsor.

Today, Kirilenko will take on Wozniacki in the first semifinal at 1 p.m., while Errani and Kvitova will play Friday evening for the other place in the final.