The 45th District was among the country's most competitive races, critical to both parties as they battled to control the House of Representatives

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.

Derek Tran, a first-time Democratic candidate, has flipped a toss-up California House seat, narrowly defeating GOP Rep. Michelle Steel, who conceded on Wednesday after a protracted vote count. Tran had declared victory early this week, and currently leads by roughly 600 votes.