​American Kate Douglass took back the world record in the 50m freestyle from training partner Gretchen Walsh in the preliminary heats, then broke it again — crushed it — in the evening final at the Pan Pacific Championships on Saturday.Douglass, the Olympic 200m breaststroke gold medalist, clocked 23.49 seconds in the prelims Irvine, California, breaking the record of 23.55 set by Walsh on June 28.Then in the final, she went 23.19 — breaking her hours-old record by three tenths of a second.Douglass previously held the world record of 23.59 set June 19, holding it for nine days before Walsh took it.SWIMMING: Results | Broadcast ScheduleOn Friday night, Douglas swam the second-fastest 100m free in history — 51.69, .01 off Dutchwoman Marrit Steenbergen’s world record — leading off the U.S. 4x100m free relay at Pan Pacs.Douglass, arguably the world’s most versatile swimmer, is also the second-fastest performer in history in the 200m breast.Kate Douglass took different strokes to swimming successKate Douglass, a Tokyo Olympic bronze medalist, is now the world’s most versatile swimmer. Nick Zaccardi,