Associated Press

The 25-year-old Diaz was awake and breathing on his own. He has been upgraded from critical to stable condition, and doctors at University Hospital are cautiously optimistic about his recovery.

"It's very exciting to see Oscar open his eyes," said Diaz's mother, Theresa. "He's a fighter, and I believe he will get better."

Diaz was unable to leave his corner for the 11th round of his fight with Delvin Rodriguez, eventually collapsing in the ring. The severe brain injuries put him in a coma after emergency surgery to relieve swelling in his brain, but doctors have expected him to survive the injuries since shortly after they occurred.