Ed Jew, a neighborhood activist whose door-to-door campaigning proved persuasive to voters, came from behind to win a closely fought race for supervisor in San Francisco's Sunset District, according to updated election results released Friday.

Jew secured a 52 percent majority, capturing 7,670 votes out of a total of 14,716 eligible ballots in San Francisco's District Four after the results of the city's ranked-choice voting were announced.

Although Jew had been trailing businessman Ron Dudum, he surged into the lead thanks to hundreds of voters who listed him as their second choice on ballots cast initially for third- and fourth-place finishers Jaynry Mak and Doug Chan.

"This is amazing," Jew said when the results were announced at City Hall shortly before 4 p.m. "This is an achievement not by myself but by the voters and my supporters. The work will begin tomorrow. We want to make sure that we serve the community."

Dudum finished second, winning almost 48 percent with 7,046 votes.

"It was a nice run," Dudum said, congratulating Jew. "We had a good race."

In the city's other closely contested contest, incumbent Supervisor Chris Daly reached the majority he needed in District Six, capturing just over 50 percent of the vote after ranked-choice ballots in that race were counted. His closest challenger, Rob Black, ended up with nearly 42 percent of the vote in that district.

Friday was the first time in city history that ranked-choice voting reordered the finishes for candidates for supervisor. But John Arntz, director of the Department of Elections, said the results are still preliminary -- about 1,500 ballots in each district have yet to be counted. The department has 28 days from the date of the election to certify final results.

Although Daly did not win by the 20-point margin he predicted, his victory repudiated recent predictions of his political demise and cemented his position as a leader of the city's progressive wing.

"San Franciscans from the east side to the west side want independent voices on the Board of Supervisors," Daly said. "I'm looking forward to my continued tenure on the board."

Daly had faced a flood of campaign mailers financed by downtown business interests trying to defeat him and suggestions by some pollsters that he was in danger of losing.

"Clearly a lot of money was spent to unseat me," Daly said. He credited his supporters with helping to get out the vote that will keep him in office. "It was their money versus our people -- our people won."

Black called Daly on Friday afternoon to congratulate the supervisor on his re-election. "I'm really proud of the race we ran," Black said later.

The results in both districts generally preserve the status quo at City Hall and deny to Mayor Gavin Newsom, who endorsed both Black and Chan, broader influence on the Board of Supervisors.

Most pundits expect Jew, a former Republican Party official who is now a registered Democrat, to practice the kind of neighborhood politics that got him elected, with a focus on crime, transit and quality-of-life issues important to the more conservative residents of District Four.

He also has criticized growth in city spending under Newsom and the progressives who control the Board of Supervisors.

Jew said he would be meeting with neighborhood groups in his district to determine legislative priorities once he takes office in January. And he pledged to work with the losing candidates and their supporters, saying, "It's important that we unite."