Serena Williams will continue her pursuit of a calendar Grand Slam tonight after the women's semi-finals at the US Open were postponed last night. Serena will face Roberta Vinci. Second seed Simona Halep meets Flavia Pennetta in the other semi final. The men's semi-finals will take place today after the conclusion of the women's matches. Top seed Novak Djokovic faces defending champion Marin Cilic first, with second seed Roger Federer taking on his fellow Swiss Stan Wawrinka in the other match. The Indo-Swiss pair of Sania Mirza and Martina Hingis has already entered the women's doubles final. In the mixed doubles final, the Indo-Swiss pair Leander Paes and Martina Hingis will face Americans Bethanie Mattek-Sands and Sam Querrey tomorrow.