Ayanna Pressley, a Boston councilwoman, defeated veteran Congressman Mike Capuano in the House Democratic primary for the 7th district in Massachusetts, AP projected, positioning Pressley to become the first black woman to serve the state in Congress.

In a race that reflected the party’s power struggle between older, white incumbents and younger, more diverse candidates, Pressley garnered 58.9% of the vote while Capuano gained 41.1%, AP reported, with 99% of precincts reporting. Pressley is backed by Alexandria Ocasio-Cortez, who defeated incumbent Rep. Joe Crowley in an N.Y. Democratic primary earlier this year.

Capuano, a 20-year House veteran, earlier conceded defeat to Pressley before AP projected the result. With no Republican running for the reliably Democratic seat, Pressley’s way is cleared for a term in office. The 7th district is overwhelmingly Democratic and takes in parts of Boston, Cambridge and Milton, plus all of Chelsea, Everett, Randolph as well as Capuano’s hometown of Somerville. It’s the state’s most racially and ethnically diverse district.

Elsewhere in Massachusetts, Geoff Diehl won the GOP Senate primary to face incumbent Democratic Sen. Elizabeth Warren, who was unopposed in her primary. Diehl, a state rep and eagle scout who served as President Trump’s Massachusetts campaign co-chair in 2016, beat rivals Beth Lindstrom, a former state consumer affairs director, and John Kingston, a former vice chairman and general counsel for Affiliated Managers Group. The nonpartisan Cook Political Report rates the Senate seat “Solid Democrat.”

Here are other noteworthy results from Tuesday night:

• MA-GOV: Jay Gonzalez won the Democratic primary for Governor and will face GOP incumbent Charlie Baker in the Nov. elections
• MA-08: Incumbent Stephen Lynch won the 8th district Democratic House primary, beating challengers Brianna Wu and Christopher Voehl. No Republican is running for the seat