He’s the first Kennedy to lose a race for Congress in Massachusetts.

Rep. Joe Kennedy III suffered a stinging defeat against incumbent Sen. Ed Markey in Tuesday’s Democratic primary.

The 74-year-old Markey, who boasts a four-decade congressional career, opened with a large lead in early returns. By 10 p.m., he had garnered 55 percent of the vote to Kennedy’s 45 percent, according to Politico.

The 39-year-old grandson of Robert F. Kennedy promised a new generation of leadership, casting Markey as out of touch after decades in Congress, first in the House and then in the Senate, beginning in 2013.