Less than one-fifth of Boston’s electorate trickled to the polls on Tuesday to pick a new crop of city councillors in an election that will bring a marked shift in the personnel and dynamics to the 13-member body. The new faces will include John FitzGerald, who posted a decisive victory over Joel Richards in the race to succeed Frank Baker as the District 3 councillor.

Councillor-at-Large Erin Murphy spoke to supporters at Blasi’s in Adams Corner on Tuesday, as Councillor Baker looked on. Seth Daniel photo

The three incumbents in the at-large field won re-election, with first-term incumbent Ruthzee Louijeune winning the most votes – 43,127 – of any candidate on Boston ballots on Tuesday. Close behind – by just 651 votes – was Erin Murphy, who saw a surge in support in her Dorchester base, but grew her vote total significantly across the city. Julia Mejia, also a Dorchester resident, finished third with about 18 percent of the vote in her third election to the council.

First-time candidate Henry Santana beat out four other candidates to fill the fourth and final at-large seat. Santana, 27, celebrated his victory in a Mission Hill restaurant alongside his chief supporter, Mayor Michelle Wu, who was another big winner in Tuesday’s voting. In addition to Santana, three other candidates she had backed were triumphant, including Sharon Durkan, a close ally who was re-elected to the District 8 seat that she had won earlier this year in a special election.

A total of 78,172 people out of the eligible 413,786 Bostonians who are registered to vote participated in Tuesday's election. That's a turnout rate of 18.89 percent.

Councillor-elect Henry Santana spoke in front of supporters at the Yellow Door Taqueria in Mission Hill on Tuesday night. He was introduced by Mayor Michelle Wu, left, who endorsed his candidacy. Chris Lovett photo

The mayor’s favored candidates also won in two more hotly contested races in Districts 6 and 5. Benjamin J. Weber won a 20-point victory over William King to succeed ousted Councillor Kendra Lara in District 6, which includes parts of Jamaica Plain and West Roxbury. In District 5, which includes a section of Mattapan and large parts of Hyde Park and Roslindale, Wu’s former aide, Enrique Pepen, beat out former Boston Police officer Jose Ruiz by about 500 votes. Pepen will replace Councillor Ricardo Arroyo, who fell out of favor with Wu this past year and was eliminated from the ballot in the September primary after she pulled her support for his re-election and backed Pepen.

Wu was on the trail with Santana frequently, including on Tuesday morning as they appeared jointly at Mattapan’s Mildred Avenue Community Center, a polling center.

After the polls closed, Adams Corner was the epicenter of celebrations in Dorchester as Erin Murphy’s supporters gathered at Blasi’s restaurant to toast her re-election while backers of John FitzGerald partied across the street at Landmark, a favored watering hole and eatery where FitzGerald once worked the door. There was plenty of foot traffic back-and-forth among voters who favored both candidates.

City Councillor Frank Baker, who did not seek re-election, introduced both FitzGerald and Murphy at their respective parties. He praised Murphy for the “practical way she looks at government. When Erin came on the city council it weas like a godsend for me,” he told Murphy’s supporters. “Erin was someone who wasn’t afraid… to take some of the difficult stances that I was taking at that point and didn’t necessarily have a lot of backing when I was taking those stances.

“Just that one person’s voice to help me, we went on to first of all, win redistricting,” Baker said to loud cheers, a reference to re-drawn city electoral maps that he and Murphy opposed and eventually succeeded in challenging in court. We were able to have real conversations about what was happening at City Hall, about how some First Amendment rights were being trampled on, in my opinion.”

Louijeune and her supporters gathered at dBar, the popular Dorchester Avenue restaurant near Freeport Street. The scene was a jubilant one as Louijeune and her parents gathered with supporters, including a band playing traditional Haitian music.

Bridget Nee-Walsh, a South Boston resident and union Ironworker, finished in fifth place in her sophomore outing as an at-large contender. Three other candidates – Clifton Braithwaite, Catherine Vitale, and Shawn Nelson rounded out the field in that order.

The Reporter’s Bill Forry, Seth Daniel, and Chris Lovett contributed to this report.