Halfbridled, seeking to regain the form she displayed during her championship season of 2003, "blew out" three furlongs in 34 4/5 seconds Wednesday in preparation for Friday's Kentucky Oaks (gr. I) at Churchill Downs."She went great," trainer Richard Mandella said of the "blow out," which is a short, quick workout within a couple of days of a major race. Halfbridled galloped out a half-mile in :48 as an extension of the official workout. "We livened her up. She had her mind on it and I am really happy about her work. Since she's been here, she's been acting like she's home. She is very happy and looks like her old self."Halfbridled is winless in two starts since securing the 2-year-old filly championship with a victory in the Breeders' Cup Juvenile Fillies (gr. I) at Santa Anita last October. The filly was withdrawn from the Ashland Stakes (gr. I) at Keeneland after developing muscle cramps.With 12 fillies entered in the $500,000, 1 1/8-mile Oaks, Mandella declined to single out one horse that has an edge over the others. "There are so many great fillies in this race," he noted.