Atlanta’s Vaughn Grissom celebrates after hitting a two-run home run Wednesday night against the Boston Red Sox. Charles Krupa/Associated Press

BOSTON — Top Atlanta prospect Vaughn Grissom homered onto Lansdowne Street in his major league debut, and Marcell Ozuna hit a three-run homer on Wednesday night to lead the Braves to an 8-4 victory over the Boston Red Sox.

Called up earlier in the day from Double-A, the 21-year-old Grissom hit the first pitch he saw in the seventh inning over the Green Monster and the seats above it and onto the street below for his first big-league hit. He tossed his bat aside before taking off around the bases, clapped his hands as he rounded third base and arrived home to be congratulated by Michael Harris II, who had singled ahead of him.

A healthy number of Braves fans in the crowd of 35,406 gave Grissom a big cheer. Grissom singled in the ninth, stole second and scored as Atlanta completed a two-game sweep.

The last-place Red Sox lost their fourth straight game, and their sixth of seven.

Kyle Wright (14-5) allowed one run on one hit and one walk in six innings, striking out five for the 10th win in 12 decisions. The reigning World Series champions, who had lost five of six games before arriving in Boston, beat the Red Sox 9-7 in 11 innings on Tuesday.

Red Sox trade deadline pickup Tommy Pham homered for the third straight game, hitting a three-run shot in the seventh to turn a 5-1 deficit into a one-run game. But the Braves scored two more in the eighth on Eddie Rosario’s double and Ozuna’s sacrifice fly.

Nick Pivetta (8-9) pitched six innings, allowing three runs – Ozuna’s home run in the fourth inning – on five hits and two walks while striking out five.

WELCOME TO THE BIGS

Grissom was batting .324 with 14 homers, 67 RBIsand 27 stolen bases at Single- and Double-A this season. He started at second base and batted ninth. He hit into a fielder’s choice in the third inning, struck out in the fifth and came up again with one on and one out in the seventh, when he homered to make it 5-1.

Harris, who was called up in May, is also a 21-year-old prospect. He entered Wednesday’s game hitting .288 with 10 homers, 34 RBI and 12 stolen bases while shoring up the defense in center field.

Harris moved up to the eighth spot in the order.

TRAINER’S ROOM

Braves: Grissom took over for Orlando Arcia, who was placed on the 10-day injured list because of a strained left hamstring he sustained running the bases in Atlanta’s 10-inning victory Tuesday night. Regular second baseman Ozzie Albies is recovering from a broken foot.

Red Sox: Shortstop Xander Bogaerts hit a foul ball off his left leg. After showing signs of pain, he remained in the game.