After his big-race successes at Royal Ascot this week, trainer Aidan O'Brien plundered the Specsavers 2 for 1 Ulster Derby with Changingoftheguard

The lightly-raced three-year-old colt came fast and late under Colm O'Donoghue to claim the premier handicap at Down Royal.

Hitting the front in the last 100 yards, the well-backed 5-2 favourite denied Drunken Sailor by two lengths.

O'Donoghue said: "Aidan will be delighted with this. He travelled well throughout and quickened up really well."

The jockey went to complete a double for O'Brien on Crowfoot in the Taxi 90 33 33 33 EBF Maiden, the 2-1 favourite romping home by four lengths.

Apprentice Gary Carroll enjoyed the first double of his career on The Tooth Fairy (4-1) and Articilitis (12-1).

The 7lb claimer struck first on The Tooth Fairy with the three-year-old beating some older rivals in the Rainbow Telecom Rated Race.

Leading inside the final furlong, the colt went on to defeat the front-running Worldly Wise by two and a half lengths.

Trainer Michael Mulvany said: "This horse is pretty versatile anywhere from five to seven furlongs and he'll probably stay a mile in time."

Carroll completed his brace on Articilitis, who got up close home to beat Ghost Mist by three-quarters of a length in the Ladbrokes.com Handicap.

"Gary gave her a cracking ride. He did all he was asked to do," said trainer Des McDonogh.

"This mare has been knocking on the door and she deserved to win. Gary's father, Raymond rode a winner for us many moons ago at Sligo."< If Paradise (9-2) defied top weight under 5lb claimer Shane Foley to take the Louis Roederer Champagne Handicap for Mick Halford.

Without a victory for more than four years until scoring at Roscommon two weeks ago, the eight-year-old made all to beat Diamond Fire by two lengths.