Steven Pateman's weight troubles cost him more than the winning ride on Palmero at Sandown on Wednesday.

Pateman forfeited rides on Palmero and Funded after advising stewards he could not make the 67kg weight for his mounts.

Stewards opened an inquiry into Pateman's latest weight offence, fining the jockey $400 for failing to fulfil his bookings.

Stewards also banned Pateman from taking rides below 67.5kg with the jockey indicating he will seek advice from a dietician.

Tom Ryan picked up both of Pateman's mounts and the Irishman guided Palmero through a dashing display in the Great Southern Steeplechase (3300m).

Palmero made his first appearance over jumps in more than 18 months after injury halted his career.

The gelding's lack of recent experience over the obstacles led him to race keenly and put in early leaps at three flights.

However, Palmero ($3.40) defeated the $3.20 favourite King Triton by 6-1/2 lengths to claim the first of three targets with trips to Oakbank and Warrnambool to follow.

"The plan was this race, the Von Doussa (Steeple) and the Brierly (Steeple)," Palmero's trainer Ciaron Maher said.

"We got the first one out of the way."

Meanwhile, Platinum Snip scored a shock win in the Jack Dow Memorial Hurdle (3300m).

Trainer Rick Freyer said the eight-year-old, who was having just his fourth start, had been too slow to race on the flat before scoring at his jumps debut as a $61 outsider.

"We used him as the lead pony because he was just too slow to race," Freyer said.

"Anyone who came to us looking for a job, we put them on Platinum Snip because he was so quiet.

"He's been all around the place in the float as a companion pony but we decided to give him another go."

Chappell dislodged jockey Paul Hamblin midway through the race but horse and rider were uninjured.