The Jason Warren-trained Bel Sonic has pressed his claims for a crack at the Magic Millions Guineas in January with a first-up victory in the opening race on Pakenham Cup day.

Bel Sonic had his first start since early September in Saturday's O'Connor Beef 3YO BM70 Handicap (1000m) and reeled in his rivals in the straight along the inside to win by half a length.

Warren is targeting a start in the Magic Millions Guineas on the Gold Coast on January 13 with Bel Sonic, who is expected to have his next start at Moonee Valley in two weeks.

"He's got untapped ability," Warren's racing manager Gerard Tesoriero said.

"He's a big gross horse and he takes a bit of work sometimes but he showed today that he got to them quite easily at about the 300-metre mark and then put the race away nicely.

"The little let-up that he's had has definitely brought his maturity on."

Bel Sonic ($9), who was racing in a one-eyed blinker for the first time, was back in the field early before making his run along the inside and defeated Spirit Of Aquada, with another 1-1/4 lengths to Elite Legacy in third.

Jockey Daniel Stackhouse said Bel Sonic had always shown ability.

The gelding was third to subsequent Group One winner Merchant Navy on debut at Pakenham in March before breaking his maiden at his next start at Geelong.

Saturday's win was his second from four career starts.

"He's a lovely horse," Stackhouse said.

"He's starting to do things right now."