World No 1 and defending champion Serena Williams was eliminated in the second round of the French Open when she suffered a 6-2 6-2 defeat against Spain's Garbine Muguruza today.The 17-times grand slam champion from the United States never got into her stride against the 20-year-old world No 35.Williams had not been knocked out of a grand slam before the fourth round since losing in the first round of the 2012 French Open.Muguruza, whose pace was too much too handle for Williams, will next face Slovak teenager Anna Schmiedlova, victor over Serena's older sister Venus.