Antonio Sanchez has conceded to Monica Ratliff in the contest to represent the east San Fernando Valley on the Los Angeles Board of Education.
Sanchez congratulated Ratliff in a Facebook posting.
"Her commitment to the children of this district is unquestionable," said Sanchez. "Her desire to raise education standards in our schools should not only be commended but also strongly supported."
Sanchez, 31, also talked about his efforts to win the seat.
"I dedicated night and day to this campaign," he said. "The past seven months have been some of the best in my life. Engaging parents, teachers, students and voters has enlivened my commitment to public service, especially for the wonderful communities in the northeast San Fernando Valley."
Sanchez was the heavy favorite because of campaigns conducted on his behalf by labor unions and the Coalition for School Reform, a political-action committee spearheaded by L.A. Mayor Antonio Villaraigosa. Ratliff could rely on only a comparative fraction of resources.
But in the preliminary final tally, Ratliff totaled 20,243 votes to 18,779 for Sanchez. The outcome was close, but not likely to be overturned by provisional ballots that remain to be counted.
Sanchez's team was not ready to concede.
"I believe there are still a large number of votes outstanding, and that could have an effect on the ultimate outcome of the race," said campaign consultant Mike Shimpock. "It is an uphill battle to be sure, but at this point, we shouldn't rule anything out."
Ratliff, meanwhile, celebrated her victory by returning to work as a fifth-grade teacher at San Pedro Elementary School.