The woman, who was not identified, was critically injured Sunday after plunging about 45 feet at O.co Coliseum. She jumped shortly after the Raiders' 23-19 loss to the Tennessee Titans and as fans were filing out of the stadium.
A good Samaritan who tried to break her fall was seriously injured in the process, but was conscious and is expected to survive, police said.
"He saved her life quite honestly, at his own expense," Alameda County Sheriff's Sgt. J.D. Nelson told the Oakland Tribune. "This guy 100 percent saved her life. She'd be dead now."
Nelson said the woman went to a seating area that was covered by a tarp and appeared to be alone when she jumped. The man who was on the concourse level saw her and repeatedly shouted, "don't do it," Nelson said.
Nelson told KTVU-TV he lunged toward the woman as she dropped. He was knocked down and was taken to a hospital with serious injuries.
The man's name was not released. Nelson told the TV station he was from Stockton, had served as a Marine and is a Raiders season ticket holder.
On the NFL opening day this year, a fan died from a fall off a pedestrian overpass outside Candlestick Park in San Francisco, and two others were injured when a railing collapsed at the Colts game against the Raiders in Indianapolis.