Setti Warren plans to serve Newton as he served his country in Iraq.

"Over the course of [my year serving Iraq], I saw some of the worst of what humanity can do and the worst of what humanity can be," Warren said as he addressed a packed Union Street restaurant at his victory party on Tuesday. "Thankfully, I returned home to Newton and was able to see the best of what humanity can do and the best of what humanity can be."

He narrowly beat state Representative Ruth Balser in the Newton mayoral elections on Nov. 3 to become the city's first black mayor.

Despite losing the Sept. 15 primary election with 30.6 percent of the votes compared to Balser's 36.1 percent, Warren turned his campaign around for the general election. Warren finished with the evening with 11,210 votes while Balser collected 10,747. Warren was able to gain enough supporters of Paul Coletti, Bill Heck and Ken Parker's campaign to beat Balser.

"[The election] didn't turn out the way we hoped, but it was really close," Balser said during her concession speech.

Balser said that she is looking forward to working with Warren in the coming months, noting that the two are "committed to [being] partners and [will] continue working for the best interest of Newton."

The Warren campaign received a boost last week after the Newton Tab endorsed him, writing that "Warren has the potential to be an outstanding mayor." Warren also received additional support from Senator John Kerry, for whom Warren was an aide.

During his victory speech, Warren attributed the success of his campaign to his door-to-door knocking. He also thanked a "special" group of North and South students who advocated on his behalf over the course of the campaign.

"We won by [463] votes, and I could walk around the room and look at the people who helped out on the campaign and literally count [463] votes that we had influenced or changed over the last nine months," senior Ben Chesler, an avid Warren supporter, said. "We really made a difference."

Chesler was a versatile member of Warren's campaign. "I helped get volunteers and interns from South and volunteered [myself]. I did phone banking, canvassing and election day stuff," Chesler said.

Though state Representative Kay Kahn was a Balser supporter, she looks forward to getting to know Warren. "We will continue to work with the School Committee, with the Board of Alderman and with the new mayor," Kahn said. "It's exciting that we have a new mayor and some new members of the School Committee to work with."

Although Warren was all smiles throughout his victory party, he recognized the tough road ahead. "This was a hard-fought campaign," Warren said in his speech. "But the real work begins tomorrow."

Chesler was one of several South students who supported Warren.

Drew Pinta, another senior, joined the campaign this past summer. "[Warren] came to my house and knocked on my door … and we kind of started talking, and he really impressed me," Pinta said. After further discussion with Warren, Pinta decided to give the campaign a try. "It was really fun so I kept on doing it," he said.

Both Chesler and Pinta agreed that Warren's name recognition and popularity skyrocketed as the campaign progressed. "Nine months ago when we were calling for Setti, even up to a few months ago, people would say, 'Who's Setti? Who is she?' As the campaign went on, we just kept picking up votes as people got to know who Setti was," Chesler said.

Neither Chesler nor Pinta was surprised to see such a narrow margin of votes between Warren and Balser. "Ruth was really about as incumbent as you can be without actually being one. She was well known [as] a state representative," Pinta said.

While Chad Radock, Balser's campaign manager, was not surprised at the slim difference in votes, he was surprised at the final outcome. "We made thousands of calls this weekend," Radock said. "I was a little disappointed to see that it didn't work out, but she was a great candidate and she proved she is one of the most successful state representatives in all of Massachusetts, and I'm very happy to have worked with her."

Warren recognized the continuing contributions of Balser during his speech, noting that she "certainly deserves our respect and appreciation for her many years of service."

While Balser continues to be an influential member of the state Legislature and a strong advocate for Newton, she plans on heading back to Beacon Hill to work for change across Massachusetts. "It's disappointing to lose but it was a very, very close election, and we worked very, very hard and we did a great job," she said. "I'm going to keep representing the people of Newton and doing all I can for the city I love … and I'm going to keep working to make sure the schools are great."