Pressley beat out Garrison for an at-large council seat previous year, but come January, Pressley likely will be trading her City Hall office for one in Washington, D.C.
There is no Republican on the November ballot in the district, meaning Pressley is virtually assured of entering Congress in January.
The race between Capuano and Pressley was perhaps the most closely watched contest in MA, especially since Pressley drew comparisons to Ocasio-Cortez.
"Pressley, who became the first woman of color ever elected to the Boston City Council in 2009, has launched her own insurgent primary challenge in MA, taking on longtime Rep. Michael Capuano in the state's 7th Congressional District", Nik DeCosta-Klipa wrote.
With Pressley off the council, Garrison may finally, after more than 20 attempts, have the chance to swoop back into an elected office.
"It seems like change is on the way", Pressley said in her celebratory speech.
Ms. Pressley becomes the second Democrat to. "These are the kind of factors that Democrats need to have over the next two months if they are going to pull off victories in some of those really competitive races".
Minority candidates could play an important role in Democratic efforts to fire up the party's most passionate supporters and offset the low turnout that midterms often draw.
State lawmakers designated the district as the first majority-minority district in MA.
But both Pressley and Capuano admit there's likely no difference between them in terms of the way they'll vote in Congress, and moreover, neither one has expressed outright opposition against Democratic leader Nancy Pelosi. U.S. Rep. Joseph Kennedy, a grandson of former Attorney General Robert F. Kennedy, also endorsed the incumbent, calling him "a guy who won't shy away from steep odds or tough truths".
Galvin will face Republican Anthony Amore in November.
Pressley will vie for a seat in the House of Representatives after a career in Boston's City Council.
MA senator Elizabeth Warren, a favourite to run in the 2020 Presidential election, was uncontested for the state's Democratic nomination. Joe CrowleyJoseph (Joe) CrowleyPressley blasts Trump as "racist, misogynistic, truly empathy-bankrupt" Ocasio-Cortez congratulates "sister in service" Pressley after Mass. primary win Capuano falls to Democratic challenger Pressley in Mass. primary MORE (N.Y.).