Wimbledon champion and world No. 1 Garbine Muguruza in action at the China Open before her first-round retirement owing to illness yesterday. She had suggested in the tournament build-up that she was not fully fit and promptly lost the first set 6-1 to unseeded Czech Barbora Strycova. The Spaniard requested a medical timeout at 2-0 down in the second set before calling it quits after having her pulse taken. US Open winner Sloane Stephens lost 6-3, 6-0 to qualifier Christina McHale in the Beijing event's first round, while former No. 1 Angelique Kerber was beaten 6-4, 6-4 by Alize Cornet in the second round.