LOS ANGELES — Sandra Bullock paid her dues in Hollywood for more than 20 years. She was rewarded Sunday, winning the best-actress Oscar for playing a tough white Southern woman who adopted a black child in "The Blind Side."

Bullock had repeatedly said she didn't think she was going to win, although the 45-year-old actress was a heavy favorite.

"Did I really earn this or did I just wear you all down?" she said after accepting the golden statue from Sean Penn.

In the closest race of the acting categories, Bullock was up against Meryl Streep in "Julie & Julia," former winner Helen Mirren in "The Last Station," and breakout stars Gabourey Sidibe of "Precious" and Carey Mulligan of "An Education" for their first-time leading roles.

Bullock had already won the Screen Actors Guild and Golden Globe awards, and tied Streep at the Broadcast Film Critics awards. Streep also won at the Globes.

At 60, Streep is the most nominated actor, male or female, of all time with 16 nods, but she's gone home empty-handed since her last best-actress win for "Sophie's Choice" in 1983. Her other victory was as supporting actress for "Kramer vs. Kramer" in 1980.

Bullock's Oscar triumph came a night after she won worst actress at the Razzies on Saturday for "All About Steve," a romantic comedy flop that quickly vanished at theaters in between her 2009 hits, "The Proposal" and "The Blind Side."

Bullock's breakout role came in the 1994 film "Speed." She went on to score box office successes in "While You Were Sleeping" and "Miss Congeniality." But she also appeared in a string of duds before a supporting role in the 2004 movie "Crash" earned Bullock some of the best reviews of her career.

Bullock became the first person to win an Oscar and a Razzie on the same weekend. She was the rare A-list star who attended the show that pokes fun at the Oscars by giving out prizes for Hollywood box office failures.

In "The Blind Side," Bullock donned a frosted blond wig and a Tennessee twang to play Leigh Anne Tuohy, the real-life adoptive mother of Baltimore Ravens football player Michael Oher. (AP)