In a heated race for the Santa Clara County Board of Education, incumbents Grace Mah and Anna Song both fended off challenges for their seats.

As the vote count trickled in overnight, Song won out over David Neighbors, a trustee in the Berryessa School District whose campaign was fueled by hundreds of thousands of dollars from charter-school backers.

The same pro-charter forces helped Mah take a comfortable lead in her campaign against challenger Dave Cortright, who was running on a platform critical of Bullis Charter School in Los Altos.

An unprecedented amount of cash -- $200,000 reported through Oct. 20 -- from charter schools and their high-tech backers fueled a vigorous attack against Song, who had opposed granting Rocketship Education permission to open 20 new charter schools.

Funds from the Santa Clara County Schools Political Action Committee paid for pro-Neighbors and anti-Song mailers and phone calls.

"It's better than I expected," Song said about the first returns showing her leading. "I didn't think I would be able to beat a quarter of million dollars."

Song and Neighbors squared off in Trustee Area 5, representing areas served by the Santa Clara, Berryessa and Milpitas school districts. Mah and Cortright were competing in Trustee Area 1, representing the areas served by the Palo Alto, Mountain View, Los Altos and Sunnyvale school districts.

The seven-member County School Board runs alternative schools for incarcerated students and for those expelled from their home districts; Head Start preschools; and special-education classes at more than 70 schools. It also provides business services such as payroll, beginning teacher support and technology for the county's 31 school districts. But recently the board has attracted attention for its approval of charter schools -- about three dozen so far, including those turned down by local school districts and then appealed to the county board.

Among the most controversial of those schools has been Bullis Charter, originally founded by parents angry at the Los Altos School District for closing the only public elementary school in Los Altos Hills. That public school has since been reopened. In the meantime, the disgruntled parents started Bullis Charter, which has been engaged in a years-long, costly legal battle with the Los Altos district over Bullis' location in modules on a junior high school campus.

The county school board granted Bullis' charter, after it was rejected by the Los Altos school board.

The county board also has attracted attention for the contracts it awarded former Superintendent Charles Weis and his successor Xavier De La Torre. Weis retired June 30 from his $332,600 a year job, then notified the county board he wanted it to take over the title to his downtown luxury condo, which he purchased with a favorable loan from taxpayers. Because the condo is worth less than what he paid for it four years ago, the county office stands to lose an estimated $175,000 if it assumes ownership.

De La Torre, who began July 1 at a salary of nearly $300,000, also received a low-interest home loan of $960,000, without any obligation to make any payments on it until he leaves his job.

Contact Sharon Noguchi at 408-271-3775. Follow her at Twitter.com/NoguchiOnK12.