Boston Mayor Thomas M. Menino, seeking a record fifth consecutive mayoral term, commandingly won a high-turnout preliminary contest last night and will now face City Councilor Michael F. Flaherty Jr. in November’s final election.

“I spoke of a new Boston miracle for our youth, new urban mechanics for our city, green jobs, and more affordable housing,” Menino said to supporters as voting results poured in. “Tonight, we stand one step closer to that vision.”

Last night’s preliminary election narrowed the mayoral field from four candidates to two. Menino, referred to by some as “Mumbles” for his thick Boston accent and history of verbal gaffes, swept roughly half the vote.

Flaherty came in second place with about a quarter, and City Councilor Sam Yoon, Boston’s first Asian-American elected official and the only Asian-American ever to run for public office in the City, finished third with approximately 20 percent of the vote. Real estate developer Kevin McCrea finished last.

Turnout in the race far exceeded the expectations of most experts, with almost 82,000 out of 350,000 eligible voters hitting the polls. In 2005, a total of 41,000 people voted in the preliminary election.

“It’s very good for democracy to have a contested mayoral contest,” said former City Councilor Lawrence S. DiCara ’71, who continues to follow Boston politics closely. “Because we’ve had arguably two viable candidates and one gadfly [in addition to Menino], people have focused on this race over the summer. It’s the first time that’s happened since 1993.”

Menino, who is sometimes jokingly referred to as “mayor for life,” came to power in 1993 and has since either run unopposed or dominated elections with a large majority of votes. He has maintained approval ratings in the low 70s over the past few years despite the economic slump and criticism of Boston’s public school system, according to surveys by the Boston Globe. A poll from May found that 57 percent of Boston residents claimed to have met the Mayor personally.

Despite his seemingly invulnerable political position, the 66-year-old Menino found himself challenged this year by three much younger candidates, all of whom promised to bring change and transparency to Boston. But Menino has thus far overwhelmed opponents using his superior campaign manpower and war chest. According to the Globe, Menino’s campaign had $939,000 to spend as of a week ago, compared to Flaherty’s $216,000.

“Flaherty will need to work very quickly to consolidate support among people who voted for Yoon, and to a lesser extent, McCrea,” DiCara said, adding that Flaherty and the Mayor are “culturally very similar” and may appeal to the same voters. DiCara noted that running against an incumbent in Boston is extremely difficult in any scenario, and said that the last time a Boston mayoral incumbent lost was in 1949.

Despite the uphill battle ahead, Flaherty called for “courage” from supporters at a victory party last night.

“The journey has just begun,” Flaherty said. “Tomorrow in Boston will be a new day.”

—Staff writer Peter F. Zhu can be reached at pzhu@fas.harvard.edu.