US Open: Caroline Wozniacki into final after Peng Shuai quits

US Open, Flushing Meadows, New York
Dates: 25 August-8 September

Caroline Wozniacki reached her second US Open final after China's Peng Shuai had to retire in stifling conditions.

The Dane was leading 7-6 (7-1) 4-3 when Peng began holding her leg in pain, and was then helped off the court for medical attention.
Peng returned 10 minutes later but could complete only five points before collapsing once again.

Peng Shuai receives treatment before leaving the court in a wheelchair

Wozniacki, the 10th seed, goes on to face Serena Williams or Ekaterina Makarova for the title on Sunday.
"It's very difficult," said Wozniacki. "You're out here and you want to battle and finish it off properly.
"I feel sorry for Peng, she played really well. It was really hot out there, it was just unfortunate she was ill."
Wozniacki had received a visit from the doctor after the third game of the second set and was given some tablets, but afterwards said: "I'm feeling pretty good.
"I've been in bed basically the last two days but fortunately we had two days off, that was a bit lucky for me."
Through to her second Grand Slam final five years after losing to Kim Clijsters at the 2009 US Open, the Dane added: "I've got goosebumps.
"It's been five years since I was in a final here and it's incredible to be back."
It was a distressing end for Peng, the doubles number three who was playing in her first Grand Slam singles semi-final.
The 28-year-old also suffered in the extreme heat of the Australian Open in January, and she left the Arthur Ashe Stadium in a wheelchair after being consoled by Wozniacki while lying at the baseline.

Caroline Wozniacki shows her concern after Peng Shuai falls to the ground moments before retiring

Peng had led in both sets only to be pegged back each time by Wozniacki, who proved much the steadier in the opening tie-break.
The Dane recovered another break early in the second and reeled off four games in a row to move within sight of victory, but she still had work to do leading 4-3 on serve.
It was at 30-30 that Peng suddenly began to suffer physically, hobbling to the back of the court and apologising to Wozniacki, who then double faulted.
Peng's condition was worsening and the trainer ran onto court to assist her, followed by officials, but when the Chinese player was helped off court it was not clear whether she would be penalised.
Wozniacki remained out in the heat of the court practising serves before saying to the umpire: "If she evaluates for half an hour, everyone could be ready again."
When Peng did re-emerge after 10 minutes she was clearly still struggling to move.
Despite somehow managing to fashion another break point among the five played, she collapsed at the baseline and a retirement inevitably followed.