Mayor-elect Martin J. Walsh celebrated his victory on Tuesday night at the Park Plaza.: Photo by Chris LovettState Rep. Marty Walsh triumphed on Tuesday in the first open race for mayor in 30 years, multiple sources tell the Reporter. Walsh, who faced off against City Councillor At-Large John Connolly, won by about 4,000 votes, sources say.

The results end a six-week battle between Dorchester and West Roxbury in a race that became increasingly bitter as Election Day drew closer. Walsh supporters frequently derided Connolly, a 40-year-old attorney, as a “corporate lawyer,” while the Connolly camp questioned whether the 46-year-old Walsh, a longtime labor leader, could stand up to the unions while in office.

Mayor Thomas Menino, who steps down in January, appeared to publicly stay out of the fight to succeed him as his supporters and donors, one by one, jumped to both camps. His press office posted on Twitter a picture of Menino on the phone with Walsh, adding, "Congratulations Mayor-elect Walsh." Connolly took to the stage after 9:30 p.m. at the Westin Copley to offer his concession speech.

Read Mayor-elect Walsh's victory speech here.

The two-man mayoral race, after a chaotic 12-person scrum in the preliminary, was defined more by the two candidates’ biographies than their policy differences, which were few: Walsh, the laborer, recovering alcoholic, and State House lawmaker who survived a stray bullet and cancer, and Connolly, a three-term councillor and former teacher who rarely deviated from a message of overhauling the city’s public schools.

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. They hit the campaign trail together in 2005, with Walsh backing Connolly’s unsuccessful first bid for City Council At-Large. Connolly got in on his second try in 2007. Both spent their careers in City Hall and the State House with at least one eye on the mayor’s seat.

After the Sept. 24 preliminary, Connolly, who jumped into the race before Menino’s exit from the election, had an early lead. But that quickly evaporated as Walsh racked up the endorsements of former rivals and elected officials of color. offered up a powerful image of him walking with former state Rep. Charlotte Golar Richie, City Councillor At-Large Felix Arroyo and former School Committee member John Barros. For his part, Connolly picked up support from some Boston clergy and had the backing of a smattering of elected officials from various parts in the city, including West Roxbury, South Boston and East Boston.

Outside groups were another factor. Pro-union groups spent millions in support of Walsh, including putting up members in hotels and canvassing. Democrats for Education Reform, which also jumped into the First Suffolk Senate special election earlier this year, also waded into the mayoral race in support of Connolly. But the group was badly outspent by labor-backed organizations.

The chilly November night marked the return of City Hall’s top job into the hands of an Irish-American, after 20 years of an Italian-American at the helm.

With over 60 percent of the vote, Menino, a Hyde Park city councillor, beat former state Rep. Jim Brett, who at the time held the seat Walsh was elected to in 1997. On that night, Boston Globe’s Marty Nolan would note the next day, the clout of the Boston Irish “sputtered to a quiet end” after 110 years in City Hall. On January 6, taking the reins in a city that has grown in diversity and economic power under Menino’s tenure, an Irish-American will be back in the chair.

Walsh's win also means there will be yet another special election in Dorchester. Walsh is expected to resign and take the mayoral chair, setting up a contest to fill his 13th Suffolk House seat.

UPDATE: Story was last updated at 9:45 p.m. with notes on the special election to replace Walsh.