Ridden by Jamie Kah, Southport Tycoon ($19) scored a widening 1-¼ length win from Veight ($4.80) with the $2.50 favourite Riff Rocket a length away third.
Maher said Southport Tycoon was the forgotten horse after his narrow defeat in the Autumn Stakes (1400m) at Caulfield on February 10.
"I was very confident last start and I almost doubted myself a little bit," Maher said.
"Jamie had the barrier (4), and I was confident she had the right barrier to bounce, land in the right spot, and she couldn't have ridden the horse any better.
"She travelled, followed Veight into the race. You know he's a genuine, genuine horse and I was very confident coming down the straight."
For the second week in succession, Kah landed the feature race on the program after winning the Blue Diamond Stakes aboard Hayasugi at Caulfield last week.