In a major victory for Democrats, first-time candidate Derek Tran defeated Republican Rep. Michelle Steel in a hotly contested Orange County congressional race that became one of the most expensive in the country.

Democrat Derek Tran has defeated Republican incumbent Michelle Steel for a House seat representing California’s Orange County and Los Angeles, NBC News projects, after a contentious race that centered on the candidates’ Asian American identities and use of aggressive anti-China messaging.

Democrats have taken control of California's 45th Congressional District from the GOP, with Republican Rep. Michelle Steel losing her Orange County House seat to Democrat Derek Tran, CBS News projects.