A dramatic renewal of the Hatton's Grace Hurdle saw Lieutenant Colonel seal a first Grade One triumph at Fairyhouse.
With Annie Power missing, the five-horse field was thinned out further when the Willie Mullins-trained favourite Zaidpour fell midway through the two-and-a-half mile contest, bringing down King of the Picts.
Punchestown Festival winner Jetson was also hampered, before recovering to challenge in the home straight, but Sandra Hughes' charge stayed on well to claim victory.
Elsewhere there was plenty to cheer for Mullins, who saddled a pair of Grade One winners in Vaiseur Lido and Nichols Canyon.
Vaiseur Lido gave jockey Bryan Cooper and Gigginstown House a double following Lieutenant Colonel's success, winning the Drinmore Novices' Chase in some style.
The five-year-old ran away from an impressive field that included favourite The Tullow Tank.
Earlier, Nichols Canyon took advantage of stablemate Allez Colombieres pulling up to record a comfortable win in the Royal Bond Novice Hurdle.
