The Spaniard has been struggling with illness which curtailed her Wuhan Open campaign last week and called time on her clash with the Czech when trailing 6-1 2-0.
Sloane Stephens is still waiting for her first win since lifting the US Open last month as the American was beaten by compatriot Christina McHale, who dropped just three games in a 6-0 6-3 success.
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Garbine Muguruza of Spain reacts before retiring due injury during the match against Barbora Strycova of Czech Republic on day three of the 2017 China Open at the China National Tennis Centre on October 1st, 2017 in Beijing, China.

Image credit: Eurosport

There was also an early exit for eighth seed Dominika Cibulkova, who was ousted 7-6 (7/4) 6-1 by Elise Mertens, and 10th seed Angelique Kerber, beaten 6-4 6-4 by Alize Cornet.
Coco Vandeweghe kept up her hopes of a place in the WTA Finals with a 6-2 6-2 success over Donna Vekic while Caroline Wozniacki made light work of Anastasia Pavlyuchenkova, winning by the same scoreline.
Shuai Peng beat Shelby Rogers 7-6 (7/3), Elena Vesnina profited from Magda Linette's retirement while Varvara Lepchenko was a 4-7 6-4 6-2 winner against Lesia Tsurenko.

Results from the China Open matches on Monday

Round 2
  • 5-Caroline Wozniacki (Denmark) beat Anastasia Pavlyuchenkova (Russia) 6-2 6-2
  • Alize Cornet (France) beat 10-Angelique Kerber (Germany) 6-4 6-4
Round 1
  • Elise Mertens (Belgium) beat 8-Dominika Cibulkova (Slovakia) 7-6(4) 6-1
  • Varvara Lepchenko (U.S.) beat Lesia Tsurenko (Ukraine) 5-7 6-4 6-2
  • Barbora Strycova (Czech Republic) beat 1-Garbine Muguruza Blanco (Spain) 6-1 2-0 (Muguruza retired)
  • 14-CoCo Vandeweghe (U.S.) beat Donna Vekic (Croatia) 6-2 6-2
  • Christina McHale (U.S.) beat 15-Sloane Stephens (U.S.) 6-3 6-0
  • Elena Vesnina (Russia) beat Magda Linette (Poland) 6-0 0-0 (Linette retired)
  • Peng Shuai (China) beat Shelby Rogers (U.S.) 7-6(3) 3-6 7-5
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