A U.S. Open Series eventFridayAt Atlantic StationAtlantaPurse: $647,675 (WT250)Surface: Hard-OutdoorSinglesQuarterfinalsJohn Isner (1), United States, def. Marinko Matosevic (8), Australia, 7-6 (8), 6-4. Benjamin Becker, Germany, def. Thiemo de Bakker, Netherlands, 6-4, 6-2. DoublesQuarterfinalsNicolas Barrientos, Colombia, and Victor Estrella Burgos, Dominican Republic, def. Chris Guccione and John-Patrick Smith (3), Australia, 7-5, 3-6, 10-6. Steve Johnson and Sam Querrey, United States, def.