A pair of new comedies aimed at distinctly different audiences took the top two spots at the weekend box office in North America, with Tina Fey's "Baby Mama" leading the charge.

According to studio estimates issued on Sunday, "Baby Mama" earned a better-than-expected $18.3 million, as young women flocked to the "Odd Couple"-style pregnancy hijinks.

The stoner sequel "Harold and Kumar Escape From Guantanamo Bay" opened at No. 2 with $14.6 million, generating buzz among male youngsters.

Last weekend's champion, the Jackie Chan-Jet Li martial-arts vehicle "The Forbidden Kingdom," fell to No. 3 with $11.2 million.

The top 10 contained one other new release, the Hugh Jackman thriller "Deception," which opened at No. 10 with a disappointing $2.2 million.

Audiences were clearly in the mood for laughs, with the bawdy comedy "Forgetting Sarah Marshall" coming in at No. 4 with $11 million in its second weekend, down two places.

Both "Baby Mama" and "Sarah Marshall" were released by Universal Pictures, which rebounded sharply from its George Clooney flop "Leatherheads" earlier this month.

The General Electric Co-owned studio said its comedies gained a foothold ahead of the busy summer season, which begins on Friday with the release of the comic book adaptation "Iron Man," starring Robert Downey Jr.

Women accounted for about 68 percent of the audience for "Baby Mama," Universal said. Fey, the star and creator of the cult TV hit "30 Rock," plays a busy executive who hires a gum-chewing, cocktail-swigging woman (Amy Poehler) to carry her baby. Reviews were generally favorable.

On the other hand, men made up 65 percent of the audience for Warner Bros. Pictures' "Harold and Kumar," which stars John Cho and Kal Penn as the bumbling heroes.

The duo's previous collaboration, 2004's "Harold and Kumar Go to White Castle," made just $18.25 million during its run in theaters. But its success on DVD meant that a sequel was a no-brainer. Warner Bros., a unit of Time Warner Inc, distributed the film on behalf of its newly downsized corporate sibling New Line Cinema.

"The Forbidden Kingdom," released by Lions Gate Entertainment Corp's Lionsgate, has earned $38.3 million after 10 days.

"Forgetting Sarah Marshall," which stars Jason Segel and Mila Kunis, has earned $35.1 million after 10 days. It dropped 38 percent from last weekend, an indication of positive word of mouth. The comedy opened at No. 1 in the U.K. this weekend with $4.1 million, Universal said.

Rounding out the top five was the Jodie Foster adventure "Nim's Island" with $4.5 million. The 20th Century Fox release has earned $39 million after four weeks. The News Corp-owned studio also released "Deception."