A relatively thin slice of Boston voters dramatically remade the Boston City Council Tuesday, awarding women and minorities a majority of seats on the 13-member body.

Two hours before the polls closed, the Boston Election Department reported that only 13 percent of those eligible to vote had cast ballots. The final vote will come in under 20 percent.

While the new demographics represent an historic shift, the ideological tilt of the largely progressive council becomes even more left leaning, reinforcing a trend seen in Suffolk County elections for the state legislature, U.S. House of Representatives, and district attorney over the last two years.

“The preference for diverse, progressive representation,” said WGBH News political analyst David S. Bernstein, “now extends into almost every Boston neighborhood.”

Big Winner: Michelle Wu

Topping the ticket for the four at-large council seats for the second consecutive time was 34-year-old Michelle Wu of Roslindale, who garnered 41,616 votes or 20.71 percent of the total.

“This is the new face of what it means to serve in Boston politics,” Wu told supporters at her Roslindale victory party, making special reference to young, first-time candidates and working mothers entering the political marketplace.

And then, taking aim at Gov. Charlie Baker (a rarity in Massachusetts politics) and President Donald Trump (a Democratic ritual), Wu said that on issues like transit and climate change, “It’s on the shoulders of city government and that special magic city government has” to bring about needed change.

Climate change, transit access, the affordable housing crunch, and a campaign to abolish the Boston Planning Development Authority were among the principle legs of Wu’s platform.

Born of Taiwanese parents in Chicago, Wu — now a mother of two — graduated from Harvard College and Harvard Law school, where she studied with Elizabeth Warren and subsequently worked on Warren’s 2012 U.S. Senate campaign.

Going into this election, Democratic activists speculated that Wu will run against two-term Mayor Marty Walsh when he is up for re-election in 2021. Neither Walsh nor Wu will discuss future plans.

On Election Day, Wu’s last stop was a joint appearance with District 7 City Councilor Kim Janey, who represents Roxbury, the South End, parts of Dorchester and the Fenway. Those neighborhoods with their African-American voters would be important targets for anyone considering a run against a well-entrenched, cash-rich incumbent such as Walsh.

At-Large Councilors

For the other two incumbents, the final results mirrored September's preliminary.

Annissa Essaibi-George of Dorchester won a third council term, coming in second with 34,054 votes, or 16.95 percent of the total.

South Boston native Michael Flaherty, the council’s longest serving member, finished just a short breath behind Essabi-George, with 33,242 votes, or 16.54 percent of the total.

As expected, Althea Garrison — an “accidental” councilor who assumed the seat vacated by Ayanna Pressley when Pressley won election to the U.S. House of Representatives last year — failed to win re-election.

The contest for the fourth at-large slot provided a relatively predictable election night with its only sense of city-wide drama.

By midnight, only 10 votes separated the fourth from the fifth-place finishers, according to City of Boston Election Department unofficial returns.

Declaring victory in a speech Tuesday night was Julia Mejia of Dorchester, who was born in the Dominican Republic, and may be the first Latina to join the council.

Alejandra Nicole St. Guillen of West Roxbury, who would be the first openly gay Latina to win a seat, conceded the seat to Mejia Tuesday, but then announced she was requesting a citywide vote recount.

Mejia and St. Guillen each scored a bit more than 11 percent of the vote.

District Councilors

Ricardo Arroyo of Hyde Park, scion of a well-known Boston political family, became the first person of color to represent Hyde Park and Roslindale's District 5, winning 5,325 votes or 54.54 percent of the total.

In District 4 (Dorchester, Mattapan, Roslindale, Jamaica Plain), Andrea Campbell, the current Council president, sailed to re-election with 87.17 percent of the total, or 4,557 votes.

In District 7 (Roxbury and the South End), incumbent Kim Janey won a commanding victory with 3,847 votes, or 74.51 percent of the total.

In District 8 (Back Bay and Beacon Hill), Priscilla Kenzie Bok took 70 percent of the total with 3,659 votes.

And in District 9 (Allston-Brighton), Liz Breadon received 3,883 votes, or 58.52 percent of the total.

Incumbent City Councilor Lydia Edwards ran unopposed in District 1; Ed Flynn in District 2; Frank Baker in District 3; and Matt O'Malley in District 6.

Clarification: This story has been updated to reflect that Wu graduated from Harvard College.