Rodriguez, who declared victory late Tuesday, was leading with 51.3 percent of the vote, with all precincts reporting. But Leon, the mayor of Ontario, had yet to concede the race.
The margin separating the candidates was 365 votes in a district where Democratic voters hold a roughly 20-percentage point registration edge.
As of Wednesday, there were nearly 800 ballots left to be counted in San Bernardino County and another 273 in Los Angeles County, according to registrars of voters in both counties.
Leon switched his party affiliation from Republican to no party preference after losing the Senate race to Torres. In the primary to fill her 52nd district seat, Democrats and their allies in organized labor were forced to commit considerable resources to get Rodriguez into the top-two.
A victory for the Pomona city councilman would move Democrats a seat away from reclaiming a two-thirds supermajority in the lower chamber after Assemblywoman Holly Mitchell of Los Angeles claims her seat in the state Senate. They could pick-up another seat on Nov. 19 if Democrat Matt Dababneh defeats Republican Susan Shelley to fill the seat vacated by Bob Blumenfield in the San Fernando Valley.
PHOTO: Freddie Rodriguez. Photo courtesy of Freddie Rodriguez for Assembly.