Ro Khanna has defeated eight-term Congressman Mike Honda, a fellow Democrat, to represent a Silicon Valley district in Washington.
Honda was considered one of most vulnerable congressional incumbents in the country as he faced a long-running House Ethics Committee probe into whether he had congressional aides perform campaign work when they were supposed to be working on government business.
Khanna led Honda by 17 percentage points with more than 100,000 ballots counted early Wednesday in California's largely Asian-American 17th district.
Khanna is a former U.S. Commerce Department official under President Barack Obama who is 35 years younger than Honda. He held a big fundraising advantage and was backed by many technology leaders.
Khanna narrowly lost to Honda in 2014 and beat him by 2 points in the June primary.