Comeback stayer De Fine Lago resurrected Grafton Cup plans after an upset win in the Dominant Handicap at Moonee Valley on Saturday.

Trainer Tony Vasil had been considering the Listed Grafton Cup (2350m) for De Fine Lago until it emerged as a target race for the Ciaron Maher-trained Mr O'Ceirin.

Vasil didn't expect De Fine Lago would be able to beat Mr O'Ceirin on Saturday but the $1.60 favourite was the first horse beaten.

Mr O'Ceirin weakened out before the home turn and finished sixth.

Swooping late to win by a nose in a three-way finish, De Fine Lago defeated Oregon Spirit and Upbeat.

Oregon Spirit was third across the line but was promoted on protest.

"That was unexpected. I was pretty much resigned to the fact that the favourite was a good thing," Vasil said.

He said he would now reconsider whether to head to the Grafton Cup on July 11.

Jockey Steven Arnold was at a loss to explain the performance of Mr O'Ceirin but said the horse probably wants it wetter.

"He was gone 800 metres out," Arnold said.

De Fine Lago hadn't won since December 2009 but Vasil was full of praise for the "tough as nails" gelding who has returned from a suspensory injury and a colic attack.

"He ran third in a Brisbane Cup, he should have won a Hobart Cup and he's had a few things go wrong with him, injury-wise," Vasil said.

"At the moment he's as sound as a bell. He's no spring chicken but he's only very lightly raced."

De Fine Lago wasn't the only horse to return to winning form on Saturday, with the Jarrod McLean-trained Blackie scoring by three-quarters of a length in the Alternate Railway Handicap (1600m).

It was the five-year-old gelding's first win since the 2011 Group Two Phar Lap Stakes when trained by Mick Kent.

The Travis Harrison Cup for apprentice riders was taken out by the Peter Moody-trained Dayita with Jake Duffy in the saddle.