Penn picked up his second career Oscar for his portrayal of the late gay-rights activist Harvey Milk in the movie "Milk," and Winslet won her first Academy Award for her performance as a former concentration camp guard in "The Reader." Penn, who previously won an Oscar for his work in "Mystic River," beat out favorite Mickey Rourke for the best lead actor gong this year.
"You commie, homo-loving sons of guns. I did not expect this," Penn declared upon accepting his trophy. "I want it to be very clear that I do know how hard I make it to appreciate me often. But I am touched by the appreciation."
Before leaving the stage, Penn gave a nod to Rourke, remarking, "Mickey Rourke rises again and he is my brother."
"Milk" also earned scribe Dustin Lance Black the Oscar for best original screenplay.
"I'd be lying if I said I hadn't made a version of this speech before. I think I was probably 8 years old and staring into the bathroom mirror and this would have been a shampoo bottle," Winslet said, referring to her statuette. "Well, it's not a shampoo bottle now. I feel very fortunate to have made it from there to here."
Penelope Cruz won for best supporting actress for her work in "Vicky Cristina Barcelona."
"Has anyone ever fainted here? Because I might be the first one," Cruz quipped as she accepted her prize.
The late Heath Ledger won the supporting actor honor for his performance in "The Dark Knight."