Day 9 #USOpen: Get your predictions in for tonight’s matchup between Serena Williams and Karolina Pliskova with a ❤️ or 🔥! Tune-in tonight at 7pm ET on @espn! _ #USOpen #tennis #sports #instatennis #instasport #karolinapliskova #pliskova #serena #serenawilliams #USOpen50