The women's semifinals took center stage in New York on Friday. At the end of the day, two close friends booked dates for the championship match at the US Open.

Wozniacki Returns to Women's Final

In the first semifinal, with windy conditions a factor, it was 10th-seeded Caroline Wozniacki against unseeded Shuai Peng of China. After a battle that included a number of long rallies, Wozniacki advanced after Peng was forced to retire due to heat illness late in the second set, trailing 7-6 4-3.

Early in the first set, both players were stingy on their serve, with neither woman threatening her opponent. However, midway through the first set, it was Peng who aggressively began to look for her opportunities. She broke the Dane to gain a 4-3 advantage but could not consolidate as Wozniacki struck back. The pair battled forward on serve, attempting to adjust to the wind.

Key points in the set came at 5-5 with Wozniacki serving. After one of several long rallies, Peng won the point following a drop shot on the line. Wozniacki, possibly feeling the effects of that rally, was ineffective on the next two points. However, Peng was unable to close out the set on her serve, following an easy Wozniacki break and the set went to a tiebreak.

In the tiebreak, Wozniacki cruised, rattling off seven straight points to take it at 7-1.

In a tournament in which Peng has been so precise with her groundstrokes and serve, she won just 48 percent of her first-serve points and yielded 19 unforced errors in the set. It was the first set that the 28-year-old had lost in the tournament.

At the beginning of the second set, Peng appeared to ratchet up her aggression and thrust Wozniacki on the run. She gained an early break but once again was unable to consolidate. Peng's service struggles continued as it appeared that she might have been nursing an injury or fatigue. She was not as quick to the ball and dropped another service game, giving Wozniacki the advantage.

Then, in a scary moment, play came to a standstill with Wozniacki serving at 4-3 30-40. Peng, clearly in distress, appeared to be suffering from heat illness and cramping. Unable to continue to the next point, she required medical attention. The Chinese woman was taken to the locker room for an off-court evaluation followed by a medical timeout. She attempted to return to play but fell to the court once more and was forced to retire. With Wozniacki showing compassion, Peng was escorted off the court in a wheelchair.

Afterwards in her courtside interview, Wozniacki was happy about her win but concerned about her opponent, “You’re out here and you want to battle and you want to finish it off properly,” she said. “I just feel sorry for Peng because she played great out there, and I hope she will be OK.”

The Dane was thrilled to advance, “I have goose bumps right now,” she said. “It's been five years since I've been in the final here, so it's incredible to be back.”

Meanwhile, tournament director David Brewer updated Peng's status shortly after the match. “Peng is in our medical facility with the doctors. She's resting comfortably and is recovering by the minute. She had a heat-related illness.”

Williams Rolls to Final

In the second semifinal, top-seeded Serena Williams faced 17th seed Ekaterina Makarova. And the American looks to be in peak form as she attempts to win her first Grand Slam of the year. Williams defeated the Russian 6-1 6-3 in just one hour.

It did not take long for Williams to gain an upper hand against the Russian as she quickly broke the big-hitting left-hander early in the first set. As the American has done so many times in the past, she steamrolled her opponent in the first set in just 26 minutes.

Things did not improve for Makarova in the second set as Williams continued her strength during service games. Meanwhile, she broke the 17th seed three times. Makarova, who had made her way to the semifinals behind her power game, saw Williams impose her will upon her. She took the set comfortably and will advance to the final once again.

Williams was thrilled. ''It feels so good. You never know. I am so happy - you have no idea,'' she said. ''I didn't think I'd be here today.''

With the victory, Williams advances to face her friend Caroline Wozniacki. She will attempt to win her third consecutive U. S. Open title. The last women to accomplish that feat was Chris Evert, who did so in the 1970s.

Williams said about the matchup with Wozniacki, “She obviously wants to win and go for her first Grand Slam. I want to win a Grand Slam for some history.”