Jockey Craig Williams has been slapped with a $2000 fine after loading Hartnell with more weight than he needed to carry in his P B Lawrence Stakes win at Caulfield.

Williams realised when he got to the barriers he was wearing a lighter vest than the one he weighed out in and picked out some tools from a nearby farrier's bag and put them in his boots.

Williams told stewards he panicked when he realised he was riding Hartnell in the lighter vest.

"I realised behind the gates that I had the light vest on and I panicked," Williams said.

"My first thought was the horse would be disqualified. I had to make up the weight."

Williams weighed out for the Group Two race at 60.1kg but weighed in at 61.3kg.

He had weighed out to ride Hartnell in the heavier vest but before going out to ride him he had also weighed out for the following race in the lighter vest.

Williams went to the farrier's bag and took out a set of clinching tongs and a buffer and put them in his boots.

Chief steward Terry Bailey said the panel had difficulty finding a precedent and the matter would have been worse had Hartnell been beaten a narrow margin.

"If it wasn't so serious it would almost be humorous," Bailey said.

"It's an unfortunate situation but it could have been worse."

Williams was fined for $1000 for altering equipment without stewards permission and another $1000 for weighing in more than a half-kilogram above his allocated weight.