US Open: Naomi Osaka takes care of business against Elise Mertens while Iva Jovic edges out good friend Alex Eala in thriller
Naomi Osaka continued to impress with her style and staying power helping her battle past Elise Mertens to reach the fourth round; <strong>watch the US Open live on Sky Sports Tennis and Sky Sports+, streaming service NOW and the Sky Sports app</strong>
