Rory Cleary brought Just For Mary, trained by Mark Loughnane, with a storming late run to claim the Ladbrokes Rockingham Handicap at the Curragh.
A course and distance winner two weeks ago when he came from last to first, the 9-1 shot was again held up before being produced to good effect to deny Senor Benny by a length.
"I know it was an unusual decision to run him while he was 7lb out of the handicap but it didn't look a great Rockingham and it was difficult to ignore such a big pot," said Loughnane. "He's improving all the time and loved the ground."
Aidan O'Brien's Black Quartz added his name to an illustrious roll of honour for the Whitney Moore EBF Maiden.
Both Teofilo and New Approach collected the seven-furlong event as juveniles while Sea The Stars was fourth on his debut last year.
Black Quartz was the mount of Johnny Murtagh when the well-bred Fighting Brave was pulled out, but the even-money favourite made most of the running for a controlled half-length defeat of Jim Bolger's Reiteration, who made a promising first appearance.
Black Quartz was installed at 25-1 for the 2000 Guineas, and O'Brien said: "He was just idling in front at the end and Johnny said the ground is very soft. He's very babyish - he improved a lot between his first and second runs and will improve again."