Review down royal 20th Jun 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.