She was facing the last player she lost to at Flushing Meadows. She kept looking up her coach, as if seeking solutions. After just 20 minutes Tuesday night, Williams was in danger of trailing by two service breaks. Not much later, the outcome was no longer in doubt, because the 23-time Grand Slam champion suddenly was in complete control.
Williams put aside some early shakiness and an early deficit, turning things around with an eight-game run en route to a 6-4, 6-3 victory over No. 8 seed Karolina Pliskova for a spot in the semifinals. It was Williams’ first win over a top-10 player this season.