The five Oscars for "Hugo," which led contenders with 11 nominations, included cinematography, art direction and visual effects.
The visual-effects prize had been the last chance for the "Harry Potter" franchise to win an Oscar. The finale, "Harry Potter and the Deathly Hallows: Part 2," had been nominated for visual effects and two other Oscars but lost all three. Previous "Harry Potter" installments had lost on all nine of their nominations.
The teen wizard may never have struck Oscar gold, but he has a consolation prize: $7.7 billion at the box office worldwide, including $1.3 billion from "Deathly Hallows: Part 2," last year's top-grossing movie.
"And yet they only paid 14 percent income tax," Oscar host Billy Crystal joked about the "Potter" franchise.
Another beloved big-screen bunch, the Muppets, finally got their due at the Oscars. "The Muppets" earned the best-song award for "Man or Muppet," the sweet comic duet sung by Jason Segel and his Muppet brother in the film, the first big-screen adventure in 12 years for Kermit the frog and company.
Earlier Muppet flicks had been nominated for four music Oscars but lost each time, including the song prize for "The Rainbow Connection," Kermit's signature tune from 1979's "The Muppet Movie."
"I grew up in New Zealand watching the Muppets on TV. I never dreamed I'd get to work with them," said "Man or Muppet" writer Bret McKenzie of the musical comedy duo "Flight of the Conchords," who joked about meeting Kermit for the first time. "Like many stars here tonight, he's a lot shorter in real life."
Filmmaker Alexander Payne picked up his second writing Oscar, sharing the adapted-screenplay prize for the Hawaiian family drama "The Descendants" with co-writers Nat Faxon and Jim Rash. Payne, who also directed "The Descendants," previously won the same award for "Sideways."
Payne said he brought along his mother from Omaha, Neb., to the Oscars, and that she had demanded a shout-out if he made it onstage.
"She made me promise that if I ever won another Oscar I had to dedicate it to her just like Javier Bardem did with his Oscar. So mom, this one's for you. Thank you for letting me skip nursery school so we could go to the movies."
Woody Allen earned his first Oscar in 25 years, winning for original screenplay for the romantic fantasy "Midnight in Paris," his biggest hit in decades. It's the fourth Oscar for Allen, who won for directing and screenplay on his 1977 best-picture winner "Annie Hall" and for screenplay on 1986's "Hannah and Her Sisters."
Allen also is the record-holder for writing nominations with 15, and his three writing Oscars ties the record shared by Charles Brackett, Paddy Chayefsky, Francis Ford Coppola and Billy Wilder.
No fan of awards shows, Allen predictably skipped Sunday's ceremony, where he also was up for best director and "Midnight in Paris" was competing in vain for best picture.
"Rango," with Johnny Depp providing the voice of a desert lizard that becomes a hero to a parched Western town, won for best animated feature.
"Someone asked me if this film was for kids, and I don't know. But it was certainly created by a bunch of grown-ups acting like children," said "Rango" director Gore Verbinski, who made the first three of Depp's "Pirates of the Caribbean" movies.
Crystal got the show off to a lively start with a star-laden montage in which he hangs out with Justin Bieber and gets a nice wet kiss from George Clooney.
Back as Oscar host for the first time in eight years, Crystal also did his signature introduction of the best-picture nominees with a goofy song medley.
Spoofing a scene from "Midnight in Paris," Bieber told Crystal he was there to bring in the 18-to-24-year-old demographic for the 63-year-old host.
Crystal's return as host seemed appropriate on a night that had Hollywood looking back fondly on more than a century of cinema history.
The top two nominees -- "Hugo" and "The Artist" -- are both love songs to early cinema.
Add the Marilyn Monroe tale "My Week with Marilyn" -- which earned Michelle Williams a best-actress nomination as the Hollywood's greatest sex goddess and Kenneth Branagh a supporting-actor nomination as Oscar winner Laurence Olivier -- and the show's producers had a ready-made script for a night of fond recollection and backslapping about show business.
Associated Press Entertainment Writers Lynn Elber and Christy Lemire contributed to this report.