Los Angeles ? “Superbad” was super good at the box office, proving that a no-name cast could hold its own amid A-list summer blockbusters.

The teen comedy from Sony, the misadventures of two high school buddies trying to score booze, took in $31.2 million to debut as the weekend’s No. 1 movie, according to studio estimates Sunday.

“Superbad” knocked off the previous weekend’s top flick, New Line’s “Rush Hour 3,” which slipped to second place with $21.8 million, raising its total to $88.2 million.

The Warner Bros. sci-fi tale “The Invasion,” starring Nicole Kidman and Daniel Craig in an update of “Invasion of the Body Snatchers,” opened a weak No. 5 with $6 million.

“Superbad” maintains the pattern of producer Judd Apatow’s earlier hits, “Knocked Up” and “The 40-Year-Old Virgin,” which he directed. Apatow and his collaborators, including “Knocked Up” star and “Superbad” co-writer and co-star Seth Rogen, have a knack for packaging crude, R-rated humor with clever, authentic dialogue far smarter than what’s normally seen in summer comedies.

“Superbad” stars Jonah Hill and Michael Cera as pals on a quest for alcohol to impress the foxy host of a party. Rogen co-stars as an inept cop who ends up carousing with the teens, while Christopher Mintz-Plasse proves a scene-stealer as Hill and Cera’s super-geeky friend.

Though centering on high schoolers, “Superbad” drew in older crowds, with 40 percent of the audience over 30, said Rory Bruer, head of distribution for Sony.

Estimated ticket sales for Friday through Sunday at U.S. and Canadian theaters, according to Media By Numbers LLC:

1. “Superbad,” $31.2 million.
2. “Rush Hour 3,” $21.8 million.
3. “The Bourne Ultimatum,” $19 million.
4. “The Simpsons Movie,” $6.7 million.
5. “The Invasion,” $6 million.
6. “Stardust,” $5.2 million.
7. “Hairspray,” $4.3 million.
8. “Underdog,” $3.6 million.
9. “Harry Potter and the Order of the Phoenix,” $3.54 million.
10. “I Now Pronounce You Chuck and Larry,” $3.5 million.