Coakley, 56, will now face Republican state Sen. Scott Brown, 50, in the final special election Jan. 19.
With about half of precincts reporting, The Boston Globe called the Democratic race for Coakley. Her 47 percent easily out-distanced U.S. Rep. Michael Capuano (28 percent), Boston Celtics co-owner Stephen Pagliuca (13 percent) and City Year co-founder Alan Khazei (13 percent).
Likewise, Brown easily turned back the challenge of Jack E. Robinson on the GOP side, the Globe said.
Turnout was reported to have been low.
The winner of January's election will take over the seat Kennedy held for 47 years. He died in August of brain cancer.