Massachusetts Sen. Ed Markey has fended off the highest-profile Democratic primary challenge of his decades in federal office, defeating the rising Rep. Joe Kennedy III, a member of the state's legendary political dynasty.

Kennedy conceded the contest nearly two and a half hours after polls closed Tuesday night. The Associated Press projected Markey as the winner a short time later.

Prior to this race, no member of the Kennedy family had lost an election in Massachusetts, according to the Cook Political Report.

Massachusetts Sen. Ed Markey held onto his Senate seat, defeating a rising star from the Kennedy dynasty in the deep blue state’s Democratic primary Tuesday.

Rep. Joseph Patrick Kennedy III, who currently represents the state’s 4th Congressional District, called Mr. Markey to concede the race about two hours after polls closed, according to multiple reports.

Senator Ed Markey beat back a bid on Tuesday from Rep. Joe Kennedy to end his nearly 50 years in elected office, humbling the Democratic Party's family dynasty that had never before lost an election in Massachusetts.