After 40 years in office - the longest term for any Congressman - the uber-liberal, ultra-vocal Pete Stark lost to a Democratic challenger - Eric Swalwell - who is an Alameda County prosecutor and nearly 50 years Stark's junior.
With all the votes in Wednesday morning, Swalwell won with 53 percent of the vote.
Stark (D-Fremont) had long championed the rights of the downtrodden and might be best known for his creation of COBRA, a continuation health insurance coverage mandate.
But over the years, the 80-year-old Congressman had gotten increasingly combative over issues and spoke without thinking.
In April, for example, Stark accused Swalwell of accepting bribes from developers, but then never provided evidence for that claim. He later apologized.
NBC Bay Area had tried to interview Stark several times before the election, but no one from his office had never called back. On Election Night, he was seen driving off in a white car without comment to anyone.
Swalwell, 31, who has been a Dublin city councilman, told NBC Bay Area on Election Day before he won that he hoped voters would choose him, and in doing so, a "new direction."
He said he was "fired up" and would be "someone who will live here and work in Washington, D.C."
Swalwell will represent the newly drawn 15th Congressional District.
Marianne Favro contributed with this report.