He tried to palm off a fake watch as a real one.
palm off
idiomTo sell or dispose of (something) with the intent to deceive; to attempt to pass off a counterfeit or inferior product as genuine.
Origin
disputed origin“Palming” an object (as in a playing card) is a type of sleight of hand, secretly removing the desired article and leaving only the undesired one.
The dishonest dealer attempted to palm off a broken camera on an unsuspecting tourist at the market.
Despite his polished sales pitch, the merchant could not palm off the inferior goods on the experienced buyer, who immediately recognized the poor craftsmanship.