Bruce Brown rates Black Magic one of the best horses he has trained.

At Eagle Farm on May 11, Brown will test that theory when he enters Black Magic for the Group One BTC Cup (1200m).

"She can break 22 seconds for her last 400 metres in trackwork and I've always felt she was among the best horses I've ever trained," Brown said.

Black Magic ($8.50) lived up to Brown's high opinion when she clinched a hat-trick of wins in Saturday's Juanmo Stakes (1200m) at Eagle Farm with Ric McMahon aboard.

"I like to space her races three weeks apart and the BTC Cup will fit into that timing," he said.

"There's also the option of a fillies and mares race the same day but I know what she's capable of and I'll definitely be throwing in an entry for the big one."

Brown has a long-held belief Black Magic is on a par with his former Golden Slipper winner Calaway Gal.

His confidence in Black Magic grew as the Eagle Farm track continued to dry out on Saturday.

"The owners thought she'd go better on a heavy track because half the field wouldn't handle it but I said to them she's at her best on top of the ground," he said.

"When the track kept improving throughout the day I thought it would be perfect for her."