For all of those dominant victories on Cathryn Sophia's resume, she still needed that signature win to solidify her credentials as one of the nation's best fillies. That status is no longer in question after she closed strong Friday to win the 142nd Kentucky Oaks and fill voids for trainer John Servis and jockey Javier Castellano. Cathryn Sophia took charge entering the stretch and rolled to her first Grade 1 victory in the $1 million showcase for 3-year-old fillies at Churchill Downs. Though her 2 3/4-length margin of victory was smaller than the previous four to start her career, her career total margin is now 41 1/2 lengths with the marquee win her connections always believed was possible. "From her first race, we knew she had a lot of talent," said Servis, who earned his first Oaks win after guiding 2004 Kentucky Derby and Preakness champion Smarty Jones. "How far she would go was always in question. The maturity that she has shown in the last three, four weeks alone, she just made the turn for the better. And she's been terrific." Seeking a rebound after running third last month in the Ashland at Keeneland, Cathryn Sophia got a good start along with race favorite Rachel's Valentina. She found her opening at the top of the stretch and overtook the fading Lewis Bay and pulled away to beat Land Over Sea with Lewis Bay third. Cathryn Sophia gave three-time defending Eclipse Award-winning jockey Javier Castellano his first Oaks win in the process and sets him up for a possible sweep Saturday in the Kentucky Derby, where he'll ride Destin. "It means a lot to me," Castellano said, "because this is my first Oaks, to win the race. In the past, I had a lot of success and finished third. ... But you always want to win the race. "You dream. You target those races, Triple Crown races. And it's a good start today." Cathryn Sophia's win also bolstered the achievements of owner Cash Is King LLC, which is 2005 Preakness and Belmont Stakes winner Afleet Alex. Cash Is King head Chuck Zacney bought the Maryland-bred for $30,000 and named her after his niece and now has a win that makes it even more special. — AP