Walsh for Boston : Reporter 2013 mayoral election coverHe survived cancer, a stray bullet, and is a recovering alcoholic. He rose from local political operative to State House lawmaker. And on Tuesday, Savin Hill’s Marty Walsh, 46, won the first open race for mayor in 30 years, becoming the first mayor from Dorchester since the John B. Hynes era of the 1950s.

Aided by a strong field organization, the endorsements of elected officials of color, union members, and millions in outside spending, Walsh bested City Councillor At-Large John Connolly by nearly 4,900 votes, winning 52 percent (72,514 votes) to Connolly’s 48 percent (67,606 votes). With 140,680 casting votes, the turnout percentage for registered voters was 38 percent. In the east-versus-west matchup between Dorchester and West Roxbury, areas like Ward 18, which includes Hyde Park and Mattapan, became a crucial battleground.

Walsh won each of Ward 18’s 23 precincts, where a hotly contested district council race boosted turnout. He also chalked up critical wins in precincts that had been carried by candidates of color— John Barros, Felix Arroyo and Charlotte Richie— in the September preliminary election.

Related: Menino, Walsh meet at City Hall

Walsh’s ground game had a ripple effect outside of the mayoral race: His supporters appeared to pull in a high number of South Boston voters for District 2 Bill Linehan, helping him defeat Suzanne Lee, a former Boston Public Schools principal who was running against the incumbent for the second time. Two years ago, Linehan won by 97 votes; on Tuesday night the unofficial tally margin was 1,072 votes.

At the Park Plaza Hotel, more than 2,000 supporters packed the ballroom, jostling for a view of the mayor-elect who was running late in making his victory speech, which came around 10:30 p.m. Walsh had a good reason: He had been speaking on the phone with President Obama and outgoing Mayor Thomas Menino, who did not run for reelection after 20 years at the helm. Walsh was invited to a Wednesday morning meeting of Menino’s cabinet.

Mayor-elect Martin J. Walsh at his victory party at the Park Plaza.: Photo by Chris Lovett

Walsh’s victory speech focused on equality and opportunity for Bostonians. “We know Boston is a strong city and a fortunate city,” he said. “My mission is to make it better, to make Boston a hub of opportunity.” He added: “I can promise you this: If we set our sights high and we work together with our ears, our minds, and our hands, then Boston, I promise you, the best is yet to come.”

The theme of the night was one of redemption. “Marty is there for each and every one of you, and Marty has always been there for folks who need a second chance,” said House Speaker Robert DeLeo, in a reference to the recovery community.

The two-man mayoral race, after a chaotic 12-person scrum in the preliminary, was defined more by the two candidates’ biographies and personal styles than by their policy differences, which were few: Walsh, the 16-year lawmaker and labor leader, and Connolly, a three-term councillor and former teacher. The two have a history together, meeting for the first time in the late 1990s when Walsh was a freshman state representative and Connolly was an intern with the Judiciary Committee. Both spent their careers in City Hall and the State House with at least one eye on the mayor’s seat.

Connolly, in his concession speech inside a small room at the Westin Copley, called Walsh a “good man” who will do “good things” for the city of Boston.

“I respect the voters’ choice,” he told reporters after his speech. Asked about his political future, Connolly, who is the son of an ex-judge and former secretary of state, said he had not thought through much beyond the time that the polls closed. “I’m going to my City Council meeting tomorrow,” he said.

Connolly then stayed at his party, shaking hands and hugging supporters whose faces were red and tear-streaked. “I’m sorry,” he said, grabbing Allston-Brighton City Councillor Mark Ciommo, who had backed him after the preliminary. “I’m sorry, brother.” He kept moving through the group of several dozen supporters, repeatedly apologizing.

Walsh's victory means there will be yet another special election in Dorchester, after a year of special elections for US Senate, state Senate, and the 12th Suffolk House. Now, Walsh’s move to City Hall will set up a contest to fill his 13th Suffolk House seat. On Tuesday night, the ballroom of the Park Plaza Hotel was already buzzing with names of those who might end up throwing their hats in the ring.

They include Dan Hunt, a Department of Conservation and Recreation aide and Ward 16 Democratic committee chairman whose father and brother have also run for the State House seat; Michael Christopher, who has worked on Gov. Deval Patrick’s reelection campaign and in the Executive Office of Public Safety; Sean Weir, the head of the Cedar Grove Civic Association; Mariama White-Hammond, executive director of Project HIP-HOP and Savin Hill resident; and Steve Bickerton, Jr., an Adams Corner resident who has been a key operative for Walsh and other local Democrats. Annissa Essaibi-George, who finished fifth in the at-large council balloting on Tuesday, also lives in the 13th Suffolk district.