SIXTH seed Madison Keys suffered a stunning first-round exit at the US Open after losing to world number eighty two Renata Zarazua of Mexico.
Reigning Australian Open champion Keys bowed out following an attritional battle with Zarazua, who prevailed 6-7 (10/12), 7-6 (7/3), 7-5.
Zarazua took advantage of Keys’ problems with her service game to claim an impressive win.
Keys gave up 14 double faults and was broken six times as Zarazua battled into a second-round meeting with France’s Diane Parry.
Keys’ defeat comes after a solid season in Grand Slams following her maiden victory at the Australian Open in January.
She reached the quarter-finals at the French Open before progressing to the third round at Wimbledon. – AFP