Elise Mertens upsets Coco Gauff in China Open quarterfinals

BEIJING — Coco Gauff said she had “no energy” in her loss to Elise Mertens at the China Open on Wednesday. The 6-3, 6-3 defeat to a player Gauff had beaten in all five of their previous matchups came days after she had received what she described as an “insane” amount of racist comments on social media following a controversial point in the preceding round. In Monday’s match against home player Sun Xinran, the fourth-ranked Gauff stopped a rally after electronic advertising boards lining the court flickered during a point late in the first set. Sun appeared about to win…