ATLANTA — Bryce Harper hit a three-run homer and the quick-scoring Nationals beat the Atlanta Braves, 8-1, on Monday night for the first 4-0 start to a season in their Washington history.

Harper’s second-inning shot off Sean Newcomb (0-1) to center field gave the Nationals a 5-0 lead. He also drew four walks and scored three runs.

For the fourth straight game as the road team, the Nationals scored in the first inning to give their starting pitcher a lead before his first pitch.

This time, the beneficiary was Tanner Roark (1-0), who allowed one run in seven innings. Roark gave up four hits with one walk and six strikeouts.

Howie Kendrick’s double to right field drove in Harper, who walked, in Washington’s two-run first inning.

Newcomb’s troubles continued in the second.

After Newcomb gave up singles to Pedro Severino and Anthony Rendon, Harper walked to the plate as stadium organist Matthew Kaminski played the somber “Imperial March.” Braves fans chimed in with boos.

Harper crushed a first-pitch fastball. The homer landed in the decorative rocks behind the 400-foot marker on the center-field wall. He has three homers — including two in Sunday’s 6-5 win at Cincinnati — and seven RBIs.

Newcomb allowed six runs, five earned, on five hits and four walks in 41/3 innings.

Braves right-hander Anibal Sanchez, whose contract was purchased from Triple-A Gwinnett before the game, pitched three scoreless innings in relief.

Nationals pinch-hitter Brian Goodwin had a two-run single off Jose Ramirez in the ninth.