The Fighting Chance (1955)

Racehorse trainer Bill Binyon and his pal, jockey Mike Gargan, are having a hard time of making ends meet when they meet Janet Wales, an attractive-but-greedy blonde, who gets them a job with "Lucky Jim" Morrison, a wealthy stable-owner. Janet plays both Bill and Mike along to the point that Mike buys her an engagement ring, but she prefers Bill and wrangles him into marrying her. Janet's extravagances and gambling drive Bill to the point of bankruptcy, and the Morrison horses are up for auction. Bill and Mike pool their resources to buy the best filly, but Janet is sure to cause some problems.