Gai Waterhouse was never going to make anything but a headline-grabbing entrance into her first Warrnambool May carnival as a jumps trainer.

The champion Sydney trainer creates a splash wherever she goes and her charge Tenby Lady provided connections and her supporters with plenty of thrills in the Callaghan Motors Maiden Hurdle (3200m) on Tuesday.

Tenby Lady was Waterhouse's first jumps runner at the famous carnival and the US-bred mare meant business from the outset.

Jockey Patrick Flood let her stride well clear of her opposition for most of the race before the testing heavy ground caused her to tire early in the straight.

Tenby Lady, the $2.70 favourite, was out on her feet in the last 150 metres but had 1-1/2 lengths to spare over Urban Explorer ($21) while Divi Filius ($26) was another 4-1/2 lengths away in third.

Waterhouse said Tenby Lady was one of the ugliest horses she had bought but the six-year-old had thrived since being prepared for a hurdle career.

"When she got home I said, `she's got a neck like a broom stick'," Waterhouse said.

"She was the ugliest thing I've ever seen but the ugly duckling can turn into a beautiful swan."

Waterhouse said she was thrilled to train a winner during the Warrnambool carnival while Tenby Lady was her second jumps winner after Valediction won at the track earlier in the month.

The Tulloch Lodge trainer said she would invest further in jumps racing and have more runners at carnivals such as Warrnambool.

"It's grassroots racing," Waterhouse said.

"Everyone here really loves their racing. They do their form and they come here to really enjoy the jumps racing."

Waterhouse will run Valediction in Wednesday's Galleywood Hurdle.