Joseph O'Brien increased his lead over Pat Smullen in the jockeys' title race to seven (85-78) with a double for his father Aidan at the Curragh.
The young jockey did not have it easy in the opening Curragh Dining & Hospitality Options 2013 Maiden even though the twice-raced Ballydoyle juvenile Kingdom was sent off the 4-11 favourite.
Always in the front rank, the son of Montjeu was pressed hard by Dermot Weld's newcomer Pay Day Kitten in the closing stages but kept on well to hold Smullen's mount at bay by a neck.
The O'Briens followed up with three-year-old newcomer Sidereus Nuncius in the Curragh Membership 2013 Maiden, the 7-2 joint-favourite sweeping past market rival September Lily in the final furlong to score by two lengths.
Smullen's best chance appeared to be on Dermot Weld's dual Grade One-winning hurdler Hisaabaat in the concluding Curragh Finale Of 2012 Handicap, in which he was sent off the 11-8 favourite.
But though he ran on strongly down the straight to finish a respectable third, he could not get to the Noel Meade-trained Leroy Parker (8-1), who was always handy and showed plenty of resolution to win by three-quarters of a length under Conor Hoban.
Easiest winner of the afternoon was Joe Murphy's Brinestine (4-1), who led approaching the furlong marker and cleared away to take the Curragh On Facebook & Twitter Handicap by eight lengths under Gary Carroll.
It was much closer for Bill Farrell's long-time leader Man Of Erin (5-1), who displayed battling qualities to fight back when headed before taking the Curragh Gift Vouchers Handicap by three-quarters of a length under Johnny Murtagh.
Danny O'Sullivan's bottom-weight Lake Louise (5-1) drifted across to the rail and then got a nice run through to beat Versilia Gal by a length and a quarter in the www.curragh.ie Nursery in the hands of Wayne Lordan.
Paul Deegan's Srucahan (12-1) pounced late to land the Go Racing In Kildare Membership Handicap, nailing Edenshaw in the shadow of the past to win by half a length under Chris Hayes.