It was a big overnight for "The Dark Knight" for Batman fans across the country, as moviegoers stormed theaters and IMAX screens to see the sequel to the 2005 blockbuster "Batman Begins."

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The film took in an estimated $18.5 million from its midnight screenings in 3,040 theaters Friday, according to Media by Numbers, besting the 2005 performance of "Star Wars Episode III: The Revenge of the Sith," which took in $16.9 million at its debut.

"The Dark Night's" overnight numbers will grow even bigger, since Media by Numbers did not include in its report the box office total for 3 a.m. and 6 a.m. screenings.

The film will expand 4,366 screens for the weekend. "Batman Begins" opened on 3,858 screens and grossed nearly $49 million its first weekend -- a number destined to be shattered by "The Dark Knight."

In Chicago, the city that doubled for Gotham for filming, a crowd of people piled out of a rented van for the midnight showing night -- their version of the Batmobile.

"We're all big comic book fans, pop culture geeks," one man said. "We figured, why not share the love?"

The film premiered at Chicago's Navy Pier, where a Batman-clad fan declared after screening the film,

Chicago television station WMAQ reported that the city's IMAX Theater is expecting record-breaking attendance as it shows the movie to sell-out crowds every three hours throughout the weekend. In fact, tickets are not available for the show until Tuesday.

The frenzy appears to be the same all over the country. According to online ticket-seller Fandango, the pre-sales for "The Dark Knight" made up 94 percent of its ticket sales this week.

The film has had fans burning with participation, fueled by critically acclaimed performance by Heath Ledger as The Joker, Batman's (Christian Bale) arch-nemesis. It was the 28-year-old Ledger's last completed screen performance before his death from an accidental overdose in January.

"It's extraordinarily bittersweet to have Heath not around and see the impression that he's making on people," director Christopher Nolan said in an @ The Movies after the film was screened for the media earlier this month. "At the same time, I have to admit to feeling great relief and so forth that people seem to be receiving the performance very much in the way the Heath would have liked and would have intended."

In South Florida, several fans dressed up like Batman or The Joker for the midnight madness. One fan, in fact, claimed he was the real Joker himself.

"Who said this is dressing up? This is what I normally wear," he said.

On the serious side, it was clear that Ledger's death was nothing to joke about.

"Unfortunately, I wish he was still around because if he did so good in this movie, imagine what he could have done in the future," said fan Nicholas Sierra.

Nolan recalled for @ The Movies that, in addition to being a great actor, Ledger was a great person.

"I think it's a great testament to his skill as an actor how different those two things were with him," Nolan said. "Anybody that knew him, knew that he was warm and gentle and lovely he was to have around, and anyone who sees The Joker he created, I think, will be blown away by the ferocity and extremity of the performance. It's an incredible piece of work."

"The Dark Knight" also stars Aaron Eckhart, Michael Caine, Gary Oldman, Maggie Gyllenhaal and Morgan Freeman.