Kimberly Birrell has suffered a disappointing loss as the clock ticks down to the US Open. (Lukas Coch/AAP PHOTOS)Kimberly Birrell has suffered a disappointing loss as the clock ticks down to the US Open. (Lukas Coch/AAP PHOTOS) Credit: AAPKimberly Birrell's preparations for next month's US Open have started with a disappointing straight-sets defeat at the WTA event in Memphis. Kasatkina, ranked 61st, was broken in both service games to open each set and six times in total. In other results, 2017 US Open champion and former world No.3 Sloane Stephens triumphed 6-4 5-7 6-2 over eighth seed Yuliia Starodubtseva.