All winter, trainer Frank Gomez insisted that he would not be tempted to run his brilliant, undefeated filly Princess Rooney in the Kentucky Derby. His objective, he said, was the 109th Kentucky Oaks. Almost nobody believed him.

But today Gomez stuck to his plan, and it was the proper decision. Princess Rooney scored the 10th consecutive victory of her career, but she didn't do it in a manner that suggested she could have beaten colts on Saturday.

Leading most of the way, she defeated Bright Crocus by 1 1/4 lengths, with Bemissed another two lengths back in third in the seven-filly field.

Princess Rooney battled for the early lead in the $179,950 Oaks with two very fast fillies, Brindy Brindy and Shamivor, and raced them into defeat after three-quarters of a mile. As soon as she disposed of them, Bemissed and Bright Crocus moved up on the turn and looked momentarily as if they might upset the 1-to-10 favorite.

But when Bright Crocus challenged, jockey Jacinto Vasquez said Princess Rooney "leveled off for me like a fresh horse." She covered the 1 1/8 miles in 1:50 4/5, not especially impressive over a very fast Churchill Downs track. She paid $2.40, $2.40 and $2.20.

Princess Rooney, who earned $116,967 for the win, has never received the attention deserving of her extraordinary record. As a 2-year-old she won all her races by an average of 11 lengths, but was outshone (or at least outpublicized) by Landaluce, the California filly who died in the fall.