Many people expected a close contest between Julie Christensen and Aaron Peskin in the race for District Three supervisor. What they didn’t expect was Peskin to win Tuesday by nearly eight points and take more than two-thirds of the precincts.

Peskin, who was the district’s supervisor from 2001 to 2009, challenged an incumbent who had the strong backing of Mayor Ed Lee but had little political experience and was prone to blunders. In the end, experience — and Peskin’s well-run campaign — won out.

“Aaron ran a flawless campaign,” said former District Three Supervisor David Chiu, who didn’t endorse either candidate. “Aaron had long and deep ties to every neighborhood in the district, organized the community extremely well, particularly in Chinatown, and I think the campaign reflected that.”

Chiu is now a state assemblyman — the race between Peskin and Christensen was to choose a successor to serve out his term as supervisor.

Christensen in North Beach

A Chronicle analysis showed that Peskin won 22 of the 30 precincts in District Three, including in Chinatown, where Christensen supporters believed the mayor’s popularity as the city’s first Chinese American mayor would translate into broad support for Christensen.

It didn’t. Instead, Christensen’s biggest margin of victory came from Russian Hill, where she won 65 percent of the vote compared with Peskin’s 33 percent. The balance went to third-place contender Wilma Pang. Christensen also beat out Peskin in North Beach by a smaller margin.

Christensen’s strong showing in those neighborhoods probably reflected her years-long work on family-friendly community projects in North Beach, including the renovation of the Joe DiMaggio Playground and the construction of the new North Beach library.

“Over the years, Julie had a strong record of working with neighborhood leaders on Russian Hill, and I think that translated into support there,” Chiu said.

But Peskin won big throughout Nob Hill and along Polk Street, areas where Christensen’s community activism arguably did not have the same resonance with voters — Peskin won every precinct in those neighborhoods.

Peskin also won close to 60 percent of the vote in Jackson Square, near the Embarcadero, where in 2013 he led the fight against a proposed residential development at 8 Washington St. Residents in that neighborhood strongly opposed the project.

The candidates split the vote on Telegraph Hill, where Peskin lives.

Peskin in Chinatown

One question during the race was how Christensen would fare in Chinatown, given that Lee appointed her to the board and supported her throughout the campaign. As the city’s first Chinese American mayor, Lee is immensely popular among Chinese voters. Christensen strategists believed they would support her because the mayor supported her.

“Ed Lee has approached godlike status” in the Chinese community, Christensen consultant David Latterman told The Chronicle in September. “Long story short: Ed Lee appointed Julie. So they like Julie. It really is that simple.”

But the mayor’s coattails weren’t as long as Latterman and others projected. Peskin won just over 50 percent of the votes in Chinatown. Latterman declined to comment on the outcome of the election or revisit his earlier analysis. Christensen’s campaign managers didn’t respond to a request for comment.

Interviews with dozens of Chinatown voters just before the election indicated Peskin was more widely known in the neighborhood, both by word of mouth and in person, and voters believed he would build more affordable housing.

Peskin also tailored his strategy to Chinese voters, promoting himself in campaign posters and spoken jingles as the “bearded man” to overcome the language barrier.

Peskin said the idea to promote himself that way came from informal surveys his campaign conducted over the summer of Chinese voters to see which candidate they favored and why. Peskin said many voters asked whether he was the “bearded man.” He was. His team ran with the idea.

Internally, Peskin’s team also said the winds shifted after a Chronicle profile of Christensen in which she suggested fellow Supervisor Jane Kim exaggerated the extent of landlords evicting poor tenants for trivial reasons. Kim then started the Twitter hashtag #DearJulieImReal, asking tenants to share their horror stories with Christensen.

Supervisor’s blunders

The Chinese media also picked up on Christensen’s comments about Kim, exacerbating the fallout. It didn’t help Christensen that she had previously used the term “lower class” when she meant to say “low income” in one of her first speeches as supervisor.

“Peskin’s message of housing and affordability resonated more with voters, particularly in Chinatown, which has become an island on a sea of gentrification,” said David Lee, executive director of the nonprofit Chinese American Voters Education Committee.

Christensen’s blunders also “fed the meme that she was out of touch and dismissive of the plight of real people and, in particular, of Chinese tenants and immigrants,” Lee said.

As of Friday, the Department of Elections showed a turnout of more than 40 percent of the district’s 34,000 registered voters. It had yet to count approximately 44,000 mail-in and provisional ballots from across the city.