Best Lass, a Pennsylvania-bred daughter of Werblin making her first start since February, stalked Mindy Queen's quick fractions of 23.13 seconds and 46.47, pounced to the front on the far turn, and pulled away for a 5 1/4-length victory in Saturday's 1 1/16-mile Prairie Meadows Oaks. Trained by Kenneth McPeek and ridden by leading rider Terry Thompson, Best Lass earned $45,000 for Magdalena Racing and returned $8.60 as the third choice in the wagering.\nFavored Ravi's Song, a fellow Kentucky shipper trained by Carl Bowman, rallied for second but could not threaten Best Lass. Locally based Whenthetimeisright, dismissed at odds of 35-1, charged home to get up for third in the field of nine, 3 1/4 lengths behind Ravi's Song.\nKarama uncorked a strong stretch rally to win the 1 1/16-mile Prairie Meadows Derby by 1 1/4 lengths from top Minnesota-bred Perfect Bull. Trained in central Kentucky by Kellyn Gorder, Karama, an emerging sophomore by Macho Uno, is now 4 for 5 lifetime with a second-place finish after taking his stakes debut.\nHeavily favored Theregoesjojo, sent off at 3-10, was pressured on the pace by locally based Ruff Stuff. Always in striking position, Perfect Bull forged clear in the stretch but could not contain Karama's four-wide thrust under Victor Lebron. Theregoesjojo stayed on to finish third, 3 1/2 lengths behind Perfect Bull.\nKarama returned a generous $15 to his backers in the field of seven. Collecting $45,000 for the Malih Al Basti Racing Stable, he is reportedly headed to the Remington Park Derby next.\nThe Oaks and Derby were part of the closing card for the mixed meet at Prairie Meadows.