City Councilor John R. Connolly topped the ticket in a hotly contested free-for-all for four at-large seats, a race that set the stage for a new generation of Hub politicians and may signal the start of the 2013 mayor’s race, experts said yesterday.

“It’s a new chapter in a whole new book of Boston politics,” said Lawrence DiCara, a former city councilor and unofficial Hub political historian. “And the next mayor’s race begins (this) morning.”

Connolly, 36, was re-elected to a second term with 51,308 votes, narrowly ahead of fellow incumbent Stephen J. Murphy, 52, who won 50,962 votes.

Connolly is viewed as an instant mayoral candidate for 2013. Top vote-getters have traditionally tried to translate their citywide appeal into mayoral bids, McCormack said.

“I think that’s silly talk by insiders,” Connolly said after the votes were counted.

First-time council candidates Felix G. Arroyo came in third with 45,099 votes, and Ayanna S. Pressley was fourth with 41,847 votes.

Arroyo, 30, is the son of former councilor Felix D. Arroyo. Pressley, 35, who also finished fourth in the September preliminary, is an aide to U.S. Sen. John F. Kerry.

“It’s all about name recognition and how they finished in the preliminary,” said Michael McCormack, another former city councilor.

Two of the four at-large seats became available when City Councilors Michael F. Flaherty and Sam Yoon opted to run for mayor instead of seeking re-election, setting off a 15-contestant melee in September before the field was whittled down to eight for yesterday’s final.

The unsuccessful four were: Tito Jackson, a Patrick administration economic development aide; Andrew Kenneally, a former aide to Flaherty; Tomas Gonzalez, a onetime Menino liaison to the Latino community; and Doug Bennett, a former Nantucket selectman.

Of the field of 15, all but Murphy are under 40, and only four are white, representing the emerging “New Boston,” DiCara said. “This is a whole new generation of people, except for Steve Murphy, who are young enough to be the son or daughter of Mayor (Thomas M.) Menino.”

Indeed, voter Susie Husted, 35, of Jamaica Plain cast two of her ballots for Arroyo and Jackson, saying she wanted new leaders. “I want to give people with new ideas an opportunity.”

The most closely watched district race had the federally indicted Chuck Turner fending off Carlos “Tony” Henriquez, 59.8 percent to 39.5 percent.

Kenneth McFadden, 37, machinist from Roxbury, said he wasn’t bothered by Turner’s indictment for allegedly taking a $1,000 bribe. Turner was able to get McFadden’s neglected street cleared of snow.

“That kind of action deserves loyalty,” he said.

Also surviving challenges were Council President Michael Ross, Sal LaMattina of the North End and Brighton’s Mark Ciommo.