By George P. Hassett

Sal DiDomenico won the rematch.
For the second time in five months, DiDomenico defeated Cambridge lawyer Tim Flaherty in a race for a state senate seat that covers two precincts in wards one and two in Somerville. DiDomenico beat Flaherty in a democratic primary yesterday after beating him by 125 votes in April to succeed Anthony Galluccio, who resigned his seat from jail after a probation violation.

DiDomenico, a former Everett alderman, previously worked as Galluccio’s chief of staff.

In another primary race yesterday, Steve Grossman, who campaigned on his experience running the family business, Somerville-based Grossman Marketing Group, won the Democratic primary for state treasurer. He will face off against Republican state Rep. Karyn Polito in the November general election.