Earlier in the day, Castellano rode at Belmont Park, before catching a plane to ride at the Altoona, Iowa track.
Racing in third, while 7-5 favorite Hillbilly Royalty set the pace, Bent On Bourbon made a strong bid for the lead on the turn for home and never looked back, scoring by three lengths to record the first stakes victory in his career. Third-choice in the wagering, Bent On Bourbon was sent off at 4-1.
"When we bought him, we thought he was something special," said owner Jamie Hill, who races under the name Bourbon Lane Stable.
Hill purchased the 3-year-old son of Arch for $90,000 at the 2013 Keeneland September Yearling Sale. After Saturday evening's win, Bent On Bourbon now owns a record of three wins from five starts with earnings of $230,400.
After losing the first two starts of his career, Bent on Bourbon now has made it three in a row, breaking his maiden at Churchill Downs May 2, before taking an optional claiming race at Churchill May 29.
"It was a beautiful trip," said Castellano, who just got to the track in Altoona, Iowa just in time. "It was a perfect trip."
Castellano also rode the colt to victory in his first win. In his debut, Bent On Bourbon finished fourth in a maiden special weight event at Gulfstream Park, then finished second April 12 at Keeneland, before starting his three race win streak.
Toby Keith's Hillbilly Royalty cut the early fractions of :23.48 and :47.43 for the half-mile, but proved no match for Bent On Bourbon, who covered 1 1/16 miles on the Prairie Meadows fast main track in 1:44.00.
Second choice Allied Air Raid rallied from sixth to get up for second by three-quarters of a length over Private Prospect, while longshot Alabaster easily beat out the tired Hillbilly Royalty for fourth. Paid Admission, Lucky Stranger, Quality Bird, Phenomenal Phoenix and Fusaichi Flame completed the order of finish.
Bent On Bourbon, who is trained by Eddie Kenneally, paid $10.80, $5, and $3.40. Allied Air Raid returned $4 and $3.40, while Private Prospect paid $6.40 to show.
Bred in Kentucky by Northwest Farms, Bent On Bourbon is out of Little Luxury, by Seeking the Gold.