Madison Keys of the United States stunned Wimbledon champion Marketa Vondrousova to reach the semi-finals on Wednesday. Keys, a US Open finalist in 2017, produced a disciplined performance to clinch a 6-1, 6-4 victory in 1hr 26min on the Arthur Ashe Stadium. The American 17th seed will play second seed Aryna Sabalenka of Belarus on Thursday for a place in the final. 

Czech ninth seed Vondrousova, who made history in July after becoming the first unseeded woman to win Wimbledon, was left ruing an inability to convert any of nine break points against Keys. Keys by contrast seized every opportunity that came her way, converting all three break points she earned to advance to the last four of a Grand Slam for the sixth time.