World number 83 Sloane Stephens clinched her maiden Grand Slam title on Saturday, defeating fellow American Madison Keys in the first all-American US Open women's singles final since 2002. Stephens beat world number 16 Keys in straight sets 6-3, 6-0 to clinch the title. The 24-year-old, who ranked 957th at the Wimbledon this year, leaves the US Open ranked 17th.