While her former husband is playing daddy in Namibia, Jennifer Aniston is basking in her new role as Hollywood's latest movie star.

Her new romantic comedy "The Break-Up," co-starring real-life companion Vince Vaughn, stunned industry observers by taking the top spot at the North American box office with ticket sales of about $38.1 million during its first three days, according to studio estimates issued on Sunday.

The Universal Pictures release, which was savaged by critics, had been expected to open in the $20 million range behind reigning champ "X-Men: The Last Stand," which slipped to No. 2 with $34.4 million in its second weekend.

Certainly, few observers were expecting it to break the former "Friends" star's mediocre run at the box office. Of her two wide releases last year, "Derailed" stalled at $36 million, while "Rumor Has It" fell silent at $43 million. Still, she has some way to go to catch up with ex-husband Brad Pitt and Angelina Jolie, the mother of his new baby girl. Their movie together, "Mr. & Mrs. Smith," earned $186 million last year.

Vaughn's last movie, "Wedding Crashers," opened to $33 million last year, and earned more than $200 million, propelled by glowing reviews and strong word of mouth.

'DUMB MOVIE'

"The Break-Up," a $52 million project that Vaughn helped write, revolves around a couple whose relationship is on the rocks, but choose to stay together in their Chicago apartment. "What's a smart comedienne doing in such a dumb movie?" asked the Wall Street Journal.

The nation's female moviegoers begged to disagree, as women comprised 67 percent of the audience, according to Universal. Exit polling also indicated that most viewers went because of the humor -- a reflection of how well Universal marketed the surprisingly dark movie.

"There is humor in it, just not the saccharine type of humor you expect," said Nikki Rocco, president of distribution at the General Electric Co.-owned studio. "People genuinely like Vince and Jennifer, and they like to be entertained."

The film is the first romantic comedy in the marketplace for a while, and actually ranks as the No. 3 opening of all time for films in this genre. "Hitch" ($43.1 million) took the crown last year from "50 First Dates" ($40 million).

'X-MEN' SPEEDS AHEAD

Elsewhere, the third "X-Men" movie has earned $175.7 million after 10 days. Its 2003 predecessor, "X2: X-Men United," took 18 days to reach that level before finishing at $215 million. The first film, 2000's "X-Men," did not get that far, ending up with $157 million. The films were released by 20th Century Fox, a unit of News Corp.., in association with Marvel Entertainment Inc.

The animal cartoon "Over the Hedge" held steady at No. 3 with $20.6 million in its third weekend. The total for the DreamWorks Animation SKG Inc.-produced animated film rose to $112.4 million. While the film has held up well, it is expected to take a big hit next weekend when Walt Disney Co. rolls out the Pixar-produced cartoon "Cars."

Meanwhile, "The Da Vinci Code" fell two places to No. 4 with $19.3 million, taking its total to $172.7 million. The film's distributor, Columbia Pictures, said it was No. 1 overseas for a third weekend with $51 million. With a foreign total of $409 million, the Vatican thriller will soon pass "Spider-Man" ($415 million) and "Spider-Man 2" ($410 million) to rank as the top international release by the Sony Corp.-owned studio.

Not so fortunate is "Mission: Impossible III," which slipped one place to No. 5 in North America with $4.7 million. The domestic total for Paramount's Tom Cruise vehicle stands at $122.7 million. By contrast, 1996's "Mission: Impossible" finished with $181 million, and 2000's "Mission: Impossible 2" with $215 million.