The Sir Patrick and Lady Justine Hogan-bred and owned Romantic Lady secured her maiden victory at Otaki on Wednesday when winning the Sunrans Spa 1200.
The daughter of Power jumped from gate six and secured an early one-one position for jockey Rosie Myers before being asked to improve at the 500m mark.
The duo took control at the turn of the straight and they didn't relinquish it, winning by three-quarters of a length over Free To Shine, with Crowning Star 1-1/4 lengths back in third.
It was the third start for the Jamie Richards-trained filly, who placed in her previous two starts, and Myers was pleased with how Romantic Lady performed.
"We didn't go that fast at all. I let her go forward around the turn and she was just dominant," she said.
"She felt like she was going to kick away but she just got a bit wayward before the end."