BEIJING–Homegrown hero Zheng Qinwen pulled out some of her best tennis to beat Ukraine’s Elina Svitolina 6-3, 7-6 (8/6) at the China Open on Friday and storm into a semi-final against Belgium’s Elise Mertens. Zheng, a wildcard entry in Beijing, finally notched her first straight-sets win of this year’s tournament, having needed more than 10