Julia Mejia, a first-time candidate for office, won the city’s fourth and final at-large seat, beating Alejandra St. Guillen 22,492 votes to 22,491 votes. Mejia welled up with tears as the Boston Election Commission announced the result, narrowing her initial eight-vote win down to one.

In a city of nearly 700,000 residents, last month’s at-large Boston City Council race was decided by a single vote Monday night in a nail-biting recount that is likely to be challenged in court.

St. Guillen had left just before the vote tally was announced to pick up her child, after several hours of legal wrangling over disputed ballots. Her team said she is reviewing the tally and her options, including whether to challenge the outcome in state court.


Mejia told reporters at City Hall moments after the result was announced that she was prepared for a legal challenge — “We should be prepared for a round three, right? The party continues,” she said — even as she was soaking in the victory and considered the matter settled.

“It really goes to reinforce the message that we’ve been promoting all along, that every vote matters,” said Mejia, an immigrant from the Dominican Republic and community activist, and the first Latina elected to the City Council. “I think now we have an amazing lesson to share with the city of Boston, how important they are in this process.”

She added, “I feel relieved because we worked so hard and because there was so many people who joined our campaign, because they wanted to believe in something.”

Earlier Monday, hours before the final tally was announced, St. Guillen and Mejia shared moments embracing each other and reflecting on the three long days of the recount, a tedious process of examining 67,011 ballots, on which each voter could choose up to four at-large candidates from the eight who advanced in the September preliminary election.


“A City Council with either of us on it is a victory for Boston,” St. Guillen said. “We will support each other, because we believe in the same values.”

The result could serve as a coda to a dramatic, monthslong campaign that spiraled into chaos on Election Night, when St. Guillen conceded the fourth and final at-large seat to Mejia with the understanding that she was behind by 200 votes. That same night, final results showed her down by only 10 votes, and the Election Commission ultimately determined she lost by eight votes, after counting provisional and military ballots.

Both St. Guillen and Mejia requested the recount, each collecting more than 50 signatures from voters in each of the city’s 22 wards for a citywide review.

The recount process involved elections workers assigned to 20 tables sorting through each ballot. The process was completed by roughly 3 p.m. Monday, after 2½ days of counting.

But legal wrangling continued late Monday, hours after city elections workers finished tallying, as the Election Commission held a hearing for two contested ballots about voter residency.

Gerry McDonough, an attorney for St. Guillen, then asked the board to reconsider decisions on more than a dozen other ballots he had contested during the recount.

The appeal was based on how voters registered their vote for Mejia. In some cases, the voter filled in the circle by her name but also wrote her name in the write-in space on the ballot, which, McDonough argued, could have invalidated the vote under state law.


The board refused to reconsider the challenges.

Dennis Newman, an attorney for Mejia, said the board had correctly viewed the voter intent.

“You have done a [proper] job in ascertaining the will of the voter,” he said, arguing that the failure to count the ballot would “disenfranchise the voters.”

Volunteers involved with St. Guillen’s campaign said that the basis of the appeal — and a possible court challenge — was that the commission had gone back and forth on how it interpreted the legal standard over the last three days. Because of its indecisiveness, they said, the board invalidated similar ballots that went for St. Guillen.

When asked, McDonough would not say whether the campaign will appeal to the courts.

“There’s political, emotional, economic consequences,” he said.

Later Monday night, St. Guillen tweeted, “We believe there are enough outstanding votes to sway the election if challenged in court, and will make a decision Tuesday on a court challenge.”

The last known recount in Boston occurred in 2001, when Felix D. Arroyo placed sixth for an at-large seat, only 33 votes behind Rob Consalvo. After the recount, he was 68 votes ahead of Consalvo, putting him in fifth place, and a year later he was elevated to the body, to fill the vacancy created when Francis “Mickey” Roache left to become Suffolk County register of deeds.


Arroyo became the first Latino elected to the council.

On Monday night, Mejia said she was proud to be elected the first Latina. She joins incumbent at-large councilors Michelle Wu, Annissa Essaibi-George, and Michael Flaherty, who took the top three spots by comfortable margins.

“For me it’s always been about building political power in low-income communities, and the more opportunities we have to demonstrate the value of our vote, the better this world is going to be,” Mejia said.

Milton J. Valencia can be reached at milton.valencia@globe.com. Follow him on Twitter @miltonvalencia.