Magic Wand has given trainer Aidan O'Brien a sixth win in the Cheshire Oaks at Chester, a recognised trial for the main event at Epsom.
One of three contenders for O'Brien, Magic came into the race a maiden after to starts but benefited from a pace-setting ride in the hands of Ryan Moore.
Smartly away on the rail, Moore made the most of his plum draw and Magic Wand could be called the winner at the top of the straight, winning by 3-1/2 lengths as the 3-1 favourite.
O'Brien's second string Forever Together took the runner-up spot after suffering a troubled passage with another Irish raider, Princess Yaiza, third for Gavin Cromwell.
"She was very smooth. Obviously she had the one stall and she got away well," Moore said.
"She will carry on improving. This was a big step up from her last run and these fillies at this time of year should be improving and I'm sure she will."
Kevin Buckley, Coolmore's UK representative, said her win was pleasing ahead of an Epsom Oaks campaign.
"As a half-sister to Chicquita (Irish Oaks winner), you'd think she'd have no problem staying further, so it bodes well for Epsom, trip-wise," he said.
Magic Wand firmed from as much as 50-1 to 14-1 for the Oaks at Epsom.