The back-and-forth Best Actor race has a winner: Eddie Redmayne, who won the Oscar on Sunday night for playing Stephen Hawking in "The Theory of Everything."

Redmayne bested Steve Carell ("Foxcatcher"), Bradley Cooper ("American Sniper"), Benedict Cumberbatch ("The Imitation Game") and Michael Keaton ("Birdman") for the honor. It was Keaton, however, who was Redmayne's stiffest competition. The veteran actor had won Best Actor at the Critics' Choice Awards and the Golden Globes (in the Musical or Comedy category), while Redmayne had triumphed at the Screen Actors Guild and BAFTA Awards, and took home Best Actor in a Motion Picture - Drama at the Globes.

"I am fully aware that I am a lucky, lucky man," Redmayne said, before expressing an uncharacteristic burst of emotion. "This belongs to all of those people around the world battling ALS. It belongs to one exceptional family [the Hawkings]. [...] I will be its custodian. I promise you I will look after him."

"The Theory of Everything" tracks Hawking's life following his diagnosis of motor neurone disease, or ALS, in 1963. Redmayne spent six months preparing to play the role, even enlisting the help of a dancer to help him with the physicality of the role.

"His mom and Jane, his wife, described the same very expressive eyebrows. So it was a lot of time in front of a mirror, basically, with Stephen on my iPad," Redmayne said in an interview with HuffPost Entertainment about his process . "Stephen, when you meet him, he has no interest in the disease. He didn't want to see a doctor ever again [after his diagnosis]. So I wanted to do all the physical stuff in prep, so when it came to filming, it was just Felicity [Jones, who plays Hawking's wife] and I playing around. Because, I hope, it's not a story about a disease, it's actually an unconventional love story."

For a full list of Oscar winners, head here .