Brown led ecologist and educator Will Pier by 1,105 votes or 2.7 percent in a surprisingly close race.
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In the 3rd District, Council on Aging CEO Shirlee Zane defeated planning commissioner Sharon Wright by 3,487 votes, or 11 percent.
In the 5th district, consumer financial educator Efren Carrillo led planning commissioner Rue Furch by about 2 percent or 3,487 votes.
Zane and Furch were backed by the Service International Employees Union Local 1021, which is in a contract dispute with the county.
The union hoped the election of Zane and Furch would lead to a review of the county's decision to require its employees and retirees to pay more of their health care premiums to close a $14 million annual deficit in those expenditures.
In Santa Rosa, certified public accountant Gary Wysocky led the field of 11 candidates for four seats on the City Council. Incumbent and Mayor John Sawyer placed second, police Lt. Ernesto Olivares placed third and former councilwoman Marsha Vas Dupre was fourth. Incumbents Lee Pierce and Carol Dean were denied re-election.
Wysocky and Vas Dupre are seen as pro-labor candidates.
Former Councilwoman Jane Bender was successful in the contest to fill two years remaining in former Mayor Bob Blanchard's term. Blanchard passed away in June. Bender, Blanchard's choice to fill his seat, garnered 45 percent of the vote and defeated three others in that race.
Cloverdale voters elected Mary Ann Brigham and re-elected Augustine Gus Wolter to the City Council, according to unofficial results. Retired business executive Luciano Toninato trailed Wolter by 2.5 percent.
Cotati voters re-elected incumbent Janet Orchard, planning commissioner Mike Kurvers and Sonoma State University professor Ronald Coleman. Electrical contractor George Barich trailed Kurvers by 24 votes.
Incumbents Mike McGuire and Gary Plass were re-elected to the Healdsburg City Council. CEO Tom Chambers won the third seat.
Former mayor and Councilman David Glass led a field of six candidates vying for three seats on the Petaluma City Council. Former Councilman Mike Healy and local business owner Tiffany Renee won the other two available seats. Incumbents Karen Nau and Samantha Freitas were defeated.
Rohnert Park Mayor Jake Mackenzie was re-elected to the council but incumbents Tim Smith and Vicki Vidak-Martinez were denied re-election. The other two winners are small business owner Gina Belforte, who led the field, and planning commissioner Joseph Callinan.
Civil attorney Guy Wilson and community volunteer Kathleen Shaffer were elected to the Sebastopol City Council. Incumbent Jen Thille and consultant Colleen Fernald fell short.
Incumbent Debora Fudge was the high vote getter among four candidates for two seats on the Windsor Town Council. Human resource specialist Cheryl Scholar won the second seat. Realtor Julie Adamson and semi-retired realty broker Lee Dysart placed third and fourth.