Magical Solution, claimed for $7,500 less than two months ago, and Emanuel De Diego, a 21-year-old riding in just the second stakes of his career, combined for a stunning upset in Sunday's $50,000 Niagara Stakes for New York-bred 3-year-old fillies at Finger Lakes. Badly beaten in her first two starts for her new connections while racing around two turns, Magical Solution ($85.50) shortened up to a sprint and rallied to overtake 1-20 favorite Helyna's My Mom by a half-length. The winning time for six furlongs on a fast track was 1:13.00. De Diego, a native of Carolina, Puerto Rico, collected his first stakes victory while riding Magical Solution for the first time. Trainer Tim Murphy claimed Magical Solution on behalf of Fat Guys Stable on May 11. Her two previous wins both came in six-furlong sprints over the inner track at Aqueduct. Helyna's My Mom, part of a heavily favored coupled entry for trainer Charlton Baker, put her head in front at the eighth pole, but was outfinished in deep stretch by Magical Solution, the longest shot on the board. Another longshot, Warmhearted Sandy, finished third at 20-1. * Earlier on the card, Elaine Castillo, 28, became the first female rider in Finger Lakes history to ride 500 winners when she guided Too Tough Jake to a 10 1/4-length victory in the seventh race.