BOSTON—At 11:07 p.m. a burst of confetti filled the 1,200-person ballroom at the Boston Park Plaza Hotel to greet Massachusetts Governor-Elect W. Mitt Romney (R), who swept State Treasurer Shannon P. O’Brien (D) about 51 to 44 percent, with 70 percent of precincts reporting.

“You carried our message across the Commonwealth. You told the voters that the mess on Beacon Hill had to be cleaned up. You said that Kerry and I were the team to do it,” said Romney, former chair of the Salt Lake City Olympic Organizing Committee.

His win comes after an extremely tight race, one that was in a statistical dead heat until yesterday.

Lt. Governor-Elect Kerry M. Healy ’82, who introduced Romney, strove to distance herself during the evening from the image of current Acting Governor Jane M. Swift.

“I have nothing in common with Jane Swift except the fact that I am female, that I hope to become Lt. Governor,” said Healy, former state party chair. “I hope that people are smart enough to realize that’s where the similarities end.”

The crowd, which had been waiting with a sense of confident anticipation, was comprised of volunteers, party activists and state party politicos, all grooving to the “New Liberty” Dixie land jazz band. Donning boaters and red vests, the band’s youngest member was a spry 60.

The evening also served as a unity event for the various branches of the Republican party, including State Rep. Michael J. Coppola (R-Foxboro), one of the few members of the Massachusetts House of Representatives who supported the candidacy of primary lieutenant gubernatorial candidate James Rappoport.

The success of his campaign relied on “lots of hard work, lots of organization, and the fact that there wasn’t anything negative said without being answered. We found that out in ’94.”

Others attributed the win to the outreach in the minority communities made by the Romney-Healy team. Gabriel J. Toussant, vice-chair of the Romney Diversity Committee, said minorities were tired of a party that “just pays lip service to you. They need to know that there is another party that gives you a good start, not a handout.”

His associate, Ray A. Owens, added that Romney’s spiritual background gave him pull among faith-based black communities. He cited Romney’s ads criticizing O’Brien’s family values that were aired on the popular gospel music channel AM 590 as an example of his strategy.

Former City Councillor Peggy Davis-Mullen, who was recently overwhelmingly defeated by Boston Mayor Thomas M. Menino for his third term, last night was heartened by the progress she had seen Romney make during the campaign.

“I am, I think, the only Democrat who endorsed him from the beginning. I am delighted with the win. His accomplishments in business show that he is the one who can bring change,” Davis-Mullen said.

Students were also excited about the breakaway win. The Harvard Republican Club was holding the biggest signs for Romney, who is a 1975 graduate of the Law School and the Business School.

“I think there are many member of the club who, through their service to the campaign, have earned a place in state government,” said Brian C. Grech ’03.

Harvard was well represented by both students and administrators.