Image Credit: Dale RobinetteGirls ruled the weekend, as the new romantic comedy No Strings Attached attracted an audience that was 70 percent female while topping the box office with $20.3 million, according to studio estimates. The R-rated Ivan Reitman movie, starring Natalie Portman and Ashton Kutcher as “friends with benefits,” was Portman’s first No. 1 picture since 2006’s V for Vendetta. CinemaScore moviegoers handed it an overall “B” rating, with women giving the modest $25 million-budget film better marks than the men they dragged along. With no upcoming romantic comedies until Adam Sandler’s Just Go with It arrives three weeks from now, Paramount is hoping that Strings can hold on to its young female base and generate a nice little run for itself.

The rest of the top five consisted of holdovers that held up, for the most part, rather well. The superhero comedy The Green Hornet fell a mild 46 percent for $18.1 million, bringing its two-week gross to $63.4 million. In third was the Vince Vaughn-Kevin James comedy The Dilemma, which followed Hornet‘s lead and dropped 45 percent for $9.7 million. The King’s Speech, which halted The Social Network awards train by winning the Producers Guild of America’s top prize Saturday night, slipped a microscopic 0.2 percent this frame. Earning $9.2 million for the weekend, the $15 million historical drama has so far collected a regal $58.6 million. And True Grit added $8 million to its box-office barbecue. The Coen brothers film has tallied $138.6 million, and the only Western ahead of it remains 1990’s Dances with Wolves, which gathered $184.2 million.

In limited release, the Peter Weir drama The Way Back, about seven World War II prisoners who escape from a Siberian labor camp, debuted to a disheartening $1.5 million from 650 theaters — a mediocre per-site average of $2,254. And the corporate-downsizing drama The Company Men, starring Ben Affleck, Chris Cooper, Kevin Costner, and Tommy Lee Jones, made $767,000 at 106 theaters for a more potent per-location average of $7,236. Check back next week as the 2012 Oscar race commences with the Jason Statham remake The Mechanic and the Anthony Hopkins horror thriller The Rite.

1. No Strings Attached — $20.3 mil

2. The Green Hornet — $18.1 mil

3. The Dilemma — $9.7 mil

4. The King’s Speech — $9.2 mil

5. True Grit — $8.0 mil