Superbad was super good over the weekend, as it claimed the U.S. box office championship.

The teen comedy from Sony, which featured no big-name stars, took in $31.2 million. It relegated the previous title-holder, Rush Hour 3, to second place with $21.8 million. Its two-week total now stands at $88.2 million.

The Warner Bros. sci-fi tale The Invasion, starring Daniel Craig and Nicole Kidman, opened a disappointing fifth with $6 million.

Superbad keeps alive the winning streak of director Judd Apatow, who has previously struck box-office gold with Knocked Up and The 40-Year-Old Virgin.

Shot on a modest $20 million budget, Superbad enjoyed a better debut than Knocked Up, which took in $30.7 in June. It has since surpassed the $100 million milestone.

Speaking August 19 to the Associated Press at Scotland's Edinburgh International Film Festival, Apatow said "I think a genuinely funny movie always has a shot at doing well, because so few movies are really funny."

Written by actor Seth Rogen and his high school best friend Evan Goldberg, Superbad tells the story of two teens on a quest for alcohol to impress the beautiful hostess of a party. Rogen co-stars as an inept cop who ends up carousing with the boys.

The top 12 movies took in $110.5 million, up 21 percent from the same weekend in 2006. Box-office tracker Media By Numbers says summer movie attendance exceeds last year by five percent.