Three other hits crowded behind: Will Smith's sci-fi smash for Warner Bros., "I Am Legend," with $16.4 million; Fox Searchlight's teen-pregnancy comedy "Juno" with $16.2 million; and 20th Century Fox's family tale "Alvin and the Chipmunks" with $16 million.
"Book of Secrets" raised its domestic total to $171 million in three weeks, putting it just $2 million shy of the total that 2004's "National Treasure" rang up during its entire run.
"I Am Legend" has grossed $228.7 million, while "Alvin and the Chipmunks" has taken in $176.7 million.
The weekend's only new wide release, the Warner Bros. fright film "One Missed Call," managed to pull in the horror-movie crowd despite universal loathing by critics. Starring Edward Burns and Shannyn Sossamon in a tale of people whose gruesome deaths are preceded by cell-phone messages recording their final moments, the movie debuted at No. 5 with $13.5 million.
The first weekend of 2008 was promising for Hollywood, continuing a holiday box-office surge that followed a weak fall season. The top 12 movies took in $123.9 million, up 18.5 percent from the first weekend of 2007.
Featuring a star-making turn from Ellen Page as a pregnant teen, "Juno" has emerged as an independent-film sensation, grabbing critical praise and building momentum as Hollywood's awards season progresses.
"It's the coolest little success story coming out of 2007," said Paul Dergarabedian, president of box-office tracker Media By Numbers. "It's playing like a mini-blockbuster right now."
The film has three nominations for next week's Golden Globes, among them best musical or comedy and an acting honor for Page.
With $52 million already in the bank, "Juno" is on its way to becoming Fox Searchlight's biggest hit ever, approaching "Little Miss Sunshine" at $59.9 million and "Sideways" at $71.5 million.
"Juno" started off in larger cities but now has caught fire in smaller towns, said Peter Rice, Fox Searchlight president.
"The middle of the country has really embraced the movie. And I think the time of year has had a magnifying effect. All the top 10 lists," Rice said. "When the press writes that it's one of the best movies of the year combined with a movie people love, I think those are the defining factors."
Breaking into the top 10 as it expanded to more theaters was Focus Features' tragic romance "Atonement," which came in at No. 10 with $5.1 million.
"Atonement" leads the Golden Globe field with seven nominations, among them best drama and acting honors for Keira Knightley and James McAvoy.
Estimated ticket sales for Friday through Sunday at U.S. and Canadian theaters, according to Media By Numbers LLC. Final figures will be released Monday.
1. "National Treasure: Book of Secrets," $20.2 million.
2. "I Am Legend," $16.4 million.
3. "Juno," $16.2 million.
4. "Alvin and the Chipmunks," $16 million.
5. "One Missed Call," $13.5 million.
6. "Charlie Wilson's War," $8.2 million.
7. "P.S. I Love You," $8 million.
8. "The Water Horse: Legend of the Deep," $6.3 million.
9. "Sweeney Todd: The Demon Barber of Fleet Street," $5.4 million.
10. "Atonement," $5.1 million.