"A Beautiful Mind" won four Academy Awards, including best picture and Ron Howard's first directing Oscar, despite being subjected to a whisper campaign about the way it handled details of the life of its central figure, John Forbes Nash Jr.
Berry became the first black performer ever to win for best actress.
In an emotionally-charged acceptance speech, she dedicated her Oscar to Dorothy Dandridge, Lena Horne and Diahann Carroll -- pioneering black actresses in Hollywood -- and to "every nameless, faceless woman of color that now stands a chance because tonight this door has been opened."
Speaking with reporters backstage, Berry was asked if her award means that Hollywood has become colorblind.
"I hope so," she said. "I never thought it would be possible in my lifetime, so I hope so."
Berry said she wasn't sure if her Oscar would change the movie industry.
"But if it changes the minds of those people who felt defeated, if they now feel hopeful," she said, "eventually those inspired hearts will make a change."
Washington became the second black ever to win for best actor. The first was Sidney Poitier, who won for "Lilies of the Field" in 1963. Poitier was honored with an honorary Oscar Sunday.
"Forty years I been chasing Sidney," Washington joked in his acceptance speech, "and what do they do? They give it to me the same night they gave it to him. There's nothing I'd rather do than chase you, Sidney."
Poitier received a standing ovation as he recalled how different Hollywood is from the way it was when he began making movies more than 50 years ago.
"Back then, no route had been established for where I was hoping to go," he said, "no pathway left in evidence for me to trace, no custom for me to follow, yet here I am this evening at the end of a journey that, when it began in 1949, would have been considered impossible."
Washington won out of a field that also featured a highly-regarded performance by Russell Crowe as Nash.
In accepting the best picture Oscar, "A Beautiful Mind" producer Brian Grazer paid tribute to Crowe's performance.
"We wouldn't be here without Russell Crowe," said Grazer.
Grazer's movie also won for best supporting actress (Jennifer Connelly) and adapted screenplay (Akiva Goldsman). The producer said he hoped the commercial and critical success of "A Beautiful Mind" would "change the way we think about and treat the mentally ill."
Jim Broadbent, a veteran British actor, won the supporting actor Oscar for his performance as John Bayley, the husband of writer Iris Murdoch in "Iris," the story of Murdoch's struggle with Alzheimer's disease.
"The Lord of the Rings: The Fellowship of the Ring" won four Oscars, after coming in with 13 nominations, more than any other picture. Producer-director Peter Jackson's adaptation of J.R.R. Tolkien's classic novel won for makeup, cinematography, visual effects and Howard Shore's original score.
Randy Newman won for best original song for "If I Didn't Have You" from "Monsters, Inc." It was Newman's first win in 16 nominations. Backstage, he was asked whether he minded breaking a winless streak that had been approaching historic proportions.
"I had mixed feelings," he joked.
Julian Fellowes won for best original screenplay for "Gosford Park."
"Moulin Rouge," producer-director Baz Luhrmann's musical about bohemian dance-hall Paris at the dawn of the 20th century, won Oscars for costume design and art direction.
"Black Hawk Down," director Ridley Scott's account of a U.S. military debacle in Somalia in 1993, won for film editing and sound. "Pearl Harbor" won for sound editing.
The Bosnian entry, "No Man's Land," won for best foreign-language film.
In addition to Poitier, the academy also presented an honorary Oscar to screen legend Robert Redford. The Oscar-winning director of "Ordinary People" used his acceptance speech to lobby his Hollywood colleagues to place a greater emphasis on freedom of expression, and less on turning a profit.
"It's a solid and healthy industry," said Redford, "but I believe it's going to be important in the years to come that we embrace the risk as well as the sure thing, to make sure that the spirit of artistic expression is alive and well."
Former academy president Arthur Hiller, the director of such movies as "Love Story" and "The Hospital," received the Jean Hersholt Humanitarian Award.
Oscar-winning actress Whoopi Goldberg hosted the telecast on ABC, making a spectacular entrance on a trapeze singing "Diamonds Are a Girl's Best Friend" and wearing a costume evocative of "Moulin Rouge" -- in which best actress nominee Nicole Kidman sang that song.
Goldberg began the proceedings using one joke to refer to two of the evening's themes -- the so-called smear campaign against "A Beautiful Mind" and the record-tying nomination of three blacks for acting Oscars.
"So much mud has been thrown this year," said Goldberg, "all the nominees look black."
In the place of big production numbers of the past, the telecast featured a performance by Cirque du Soleil that included aerial artists working without a net -- above the audience in the Kodak Theatre. And instead of spacing performances of Oscar-nominated songs throughout the show, producers clustered all the performances together in one spot.
Still, the unofficial running time of the telecast was 4 hours, 21 minutes. That easily breaks the old record, 4 hours, 9 minutes, set in 1999.
Among the evening's surprises was the first appearance on an Oscars telecast by Woody Allen, who has never shown up for the event, even in years when he was nominated -- including when he won for best picture and best director with "Annie Hall."
Allen introduced a film by writer-director Nora Ephron paying tribute to New York City. Thanking the audience for its applause, Allen made a joke about the tight security surrounding the Oscars.
"Thank you very much," he said. "That makes up for the strip search."
Speaking with reporters backstage, Allen said it was only the opportunity to do something for his beloved New York City, following the terrorist attack of Sept. 11, that prompted him to make the trip.
"It was hard, but I wanted to do something for New York and the opportunity presented itself to me sort-of on a silver platter," he said. "We've had such a tough time of it there I couldn't resist it."