Hollywood's finest hit the Oscars red carpet Sunday as the sun emerged just in time for the 86th Academy Awards, the most fiercely contested show in decades with no clear frontrunner for the top prize.
Storm clouds which had threatened to rain on the pre-show celebrity fashion parade mostly lifted, as stars headed along the Hollywood Boulevard runway for the climax of Tinseltown's annual awards season.
Harrowing historical drama "12 Years a Slave," 3D space thriller "Gravity" and 1970s crime caper "American Hustle" are hotly tipped to take the top prizes at Sunday night's show, starting at 5:30 pm (0130 GMT Monday).
Briton Chiwetel Ejiofor, up for best actor for "12 Years a Slave," was among the early arrivals, as were "American Hustle" star Amy Adams -- in deep blue Gucci -- and Ejiofor's co-star Lupita Nyong'o, up for best supporting actress and stunning in pale blue Prada.
- 'Surreal moment'' -
"It's quite a surreal moment," Ejiofor told CNN, adding that "it would be amazing" to win. But he stressed: "One of the proudest things... is that people have received the film in the spirit in which it was made."
Academy President Cheryl Boone Isaacs told AFP: "This has been an incredible year for films. We see it with the foreign-language films and the documentary films, animated films, live-action films.
"It's really been a fantastic year."
On the acting front, Cate Blanchett is favorite for her turn in Woody Allen's "Blue Jasmine," while Matthew McConaughey is widely fancied to strike Oscars gold for his portrayal of homophobic HIV-positive AIDS activist Ron Woodroof in "Dallas Buyers Club."
Jared Leto's role as Woodroof's unlikely transgender business partner has put him ahead of the field for best supporting actor, and Nyong'o could take home a statuette for her big-screen debut in "12 Years a Slave."
"My heart is telling me it's going to be a good night," Nyong'o told CNN.
- 'Very intense season' -
On the eve of Hollywood's biggest night, "12 Years a Slave" scored a last-minute boost by winning best feature and best director for Briton Steve McQueen on Saturday at the Independent Spirit Awards.
McConaughey, Leto, Blanchett and Nyong'o took home the acting awards, further cementing their status as the ones to beat for the prized Oscar statuettes.
But experts agree that, while some categories may be seemingly settled, all bets are off for the big prize of the night, the best picture Oscar, which will be handed out at the end of the show hosted by US talk show host Ellen DeGeneres.
"It's been a very intense season because there's been so many good films," industry journal Variety's awards editor Tim Gray told AFP in the run-up to the Oscars.
"The very last envelope that's opened is going to be very suspenseful."
The 6,000 or so voting members of the Academy of Motion Picture Arts and Sciences cast their ballots over 12 days starting on Valentine's Day and ending on Tuesday.
- Too close to call -
The best picture race is so close that the winner could come down to only a few votes, under the Academy's preferential voting system. Under the rules, voters rank all nine nominated films.
They are: "American Hustle," "Captain Phillips," "Dallas Buyers Club," "Gravity," "Her," "Nebraska," "Philomena," "12 Years a Slave" and Martin Scorsese's "The Wolf of Wall Street."
Those with the least first-place votes are dropped, and their votes given to the next highest-ranked nominees. This continues until one movie has 50 percent plus one vote.
Topping nominations are "American Hustle" and Mexican director Alfonso Cuaron's "Gravity," with 10 nods apiece, followed by "12 Years a Slave," a true story of a free black man sold into slavery, with nine.
Cuaron is the frontrunner for the best director prize, and his star Sandra Bullock earned high praise for her work in the spectacular space drama, prompting some to suggest she could cause an upset in the best actress race.
But Australia's Blanchett remains the firm favorite in that category, despite a strong field also containing Meryl Streep ("August: Osage County"), Judi Dench ("Philomena") and Amy Adams ("American Hustle").
- Golden Raspberries -
The star-studded Oscars broadcast will feature performances by Irish rockers U2, playing their nominated song from "Mandela: Long Walk to Freedom," and a first Oscars turn by veteran Bette Midler.
The anti-Oscars Razzies were handed out Saturday for Hollywood's worst films of 2013.
Sci-fi flop "After Earth" starring Will Smith and son Jaden earned three Golden Raspberries, while spoof comedy compilation "Movie 43" won worst picture, in Hollywood's annual hall of shame.