The penultimate day of this year's US Open sees three huge matches take place at Flushing Meadows, New York.
First up are the two men's semi-finals before the women take centre stage in their final under the floodlights of the Arthur Ashe Stadium.
However, the matches have been brought forward an hour with the threat of storms in the Big Apple.
Here's the order of play for day 13 of the US Open.
Arthur Ashe Stadium (4pm start)
Tomas Berdych vs. Andy Murray - men's semi-final
David Ferrer vs. Novak Djokovic - men's semi-final
Victoria Azarenka vs. Serena Williams or Sara Errani - women's final
