Previous Potter flick Order of the Phoenix managed a relatively embarrassing $12 million from midnight screenings in 2007, on its way to a $139.7 million opening weekend.
The midnight record was stolen from last year’s release The Dark Knight, which managed $18 million.
Half-Blood Prince also trumps Transformers: Revenge of the Fallen opening night midnight screening grosses of $16 million.
UPDATE: Harry Potter and the Half-Blood Prince scored a gargantuan $4.37 million on its first day of release in Australia. That makes it the third-highest opening day gross of all time within the nation.
Discuss: What were your thoughts on Harry Potter 6? Does it deserve to triumph over TDK and Transformers 2?