Green Lantern Stables’ homebred Frostmourne, developed at the barn of Mickey Preger Jr. at the Camden Training Center, upset favorite Big Score to win Saturday’s $500,000 Penn Mile (Grade 2) by 1 1/4 lengths under jockey Irad Ortiz, Jr. The 3-year-old son of Speightstown was clocked over Penn National’s firm turf in 1:35.04 for trainer Christophe Clement. It was the first graded stakes victory for Frostmourne. The Penn Mile was the feature race on a dayy of stakes racing at Hollywood Casino at Penn National Race Course.