Ben Stiller’s “Night at the Museum” took first place at the box office, debuting with $30.8 million to lead a rush of new movies over the holiday weekend, according to studio estimates.

The initial estimates didn’t take into account “Dreamgirls” and “Black Christmas,” which rolled out on Monday.

In “Night at the Museum,” Stiller stars as a guard at a museum where exhibits come alive at night. The comedy exceeded expectations for 20th Century Fox, which had been counting on a bit more than $20 million, said head of distribution Bruce Snyder.

The previous weekend’s No. 1 movie, Sony’s “The Pursuit of Happyness,” slipped to second with $15 million, raising its 10-day total to $53.3 million.

Sylvester Stallone’s “Rocky Balboa” lived up to its underdog theme, overcoming geriatric-boxer jokes to debut at No. 3 with a solid $12.5 million over the weekend and a total of $22.1 million since opening Wednesday.