Given a peach of ride by an in form Joao Moreira, Signoff pounced on the lead inside the 300 metres to draw away from Big Memory by 2 1/2 lengths with La Amistad 2 lengths back in third (photos Lisa Grimm).
It was the first stakes win for the Darren Weir-trained gelding and some bookmakers were impressed enough to promote him to the top line of betting in the Melbourne Cup.
The winner of five of his six starts last season, Signoff was breaking through for his first win this term.
After failing in the JRA Cup, Signoff finished second to Big Memory in the Group II Herbert Power Stakes (2400m) at Caulfield on October 11 then was third behind fellow imports Contributer and Noble Protector in the Group III David Jones Cup (2000m) a week later.
"It was a great ride by Jo. He did a bit of work out of the barrier but I told him to be first four, preferably off the fence if you can and then he made them work to get around him," Weir said.
"He got into a lovely rhythm down the back and he (Moreira) produced him at the right time,
"The horse was nice and strong through the line and he looked to have a nice day out ahead of Tuesday.
"Big thank you to all the staff down at Warrnambool, they've done all the work with him."
Purchased in Europe by bloodstock agent John Foote, Signoff is by English Derby winner Authorized (IRE). The son of Montjeu shuttled to Darley for four years (2009-2012) where he sired Spring Champion Stakes winner Complacent.
Bred by Darley, Signoff is a brother to Tamarrud who had the honour of becoming the first winner for Authorized when he scored over 1600 metres at Lingfield in back in August 2011.
They are out of the Gone West mare Miss Hepburn who hails from the family of St Leger winner, and Darley's Japanese-based stallion Rule of Law.