Democrat Fullerton Mayor Doug Chaffee pulled 9 votes ahead of Republican La Habra Mayor Tim Shaw on Friday, turning the contest for an open seat on the all-GOP Orange County Board of Supervisors into a virtual tie.

Chaffee, who if elected would be the first Democrat on the board in a dozen years, trailed by 1,600 votes on election night but closed the deficit as ballot’s tallied since Nov. 6 have trended his way.

The two mayors are competing for the county’s northeast 4th District seat that’s being vacated by termed-out GOP Supervisor Shawn Nelson. The 4th District spans Fullerton, La Habra, Brea, Placentia, and parts of Anaheim and Buena Park.

Chaffee said his post-election surge makes it appear he’s headed for a win. But he also said he won’t claim victory unless he’s still ahead when the election is certified.

“I expect the trend to continue,” Chaffee said.

Shaw said he’s hoping that provisional ballots — most of which remain uncounted — will mirror the results of other ballots cast on Election Day, which broke in his direction.

“I’m just going to wait and see,” Shaw said.

The 4th District has shifted from red to blue in recent years.

Five years ago, Republicans held a voter registration advantage in the seat. By 2014, Democrats had taken a slim 1-percentage-point voter registration lead in the district, but Nelson still easily won re-election with 83 percent of the vote.

Now, Democrats have a 10.6-point registration advantage in the district and are positioned to take the seat if late vote tallies trend toward the party. Provisional and late vote-by-mail ballots counted post-election traditionally favor Democrats over Republicans in California due to voting patterns and recent registration efforts.

Chaffee has framed his candidacy as a chance for 4th District constituents to shake up the composition of the all-GOP board. He has criticized sitting supervisors for not addressing the region’s ballooning homeless problem sooner. And he has said his ties to public labor will help give him a different approach than the current board.

Shaw has touted his extensive government experience on regional boards, such as the Orange County Transportation Authority and the Association of California Cities Orange County. Shaw has said his connections to the four sitting supervisors – all of whom endorsed him – would give him a leg up in addressing constituents’ concerns.

Orange County will hold a special election in January or February to pick a replacement for 3rd District Supervisor Todd Spitzer, who this month was elected as the county’s new District Attorney.