Caroline Wozniacki celebrates after defeating Shuai Peng of China in the women's singles semifinal match.
Caroline Wozniakci plays a backhand during her semis match.
Wozniacki advanced after China's Peng Shuai pulled off due to heat exhaustion in the second set and trailing 7-6(1), 4-3.
Top seeded Serena Williams overpowered Ekaterina Makarova 6-1, 6-3 in the semifinal match of US Open.
Ekaterina Makarova in action during the women's semifinal match at the US Open.
Serena Williams in action against Makarova during her semis match of US Open.