BOSTON -- Top Atlanta Braves prospect Vaughn Grissom homered onto Lansdowne Street in his major league debut, and Marcell Ozuna hit a three-run homer on Wednesday night to highlight 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.

"I didn't feel a thing. I didn't feel one thing," Grissom said of his home run during his on-field, postgame interview on Bally Sports South. "Literally, I hit it, and blacked out until I saw my first-base coach, and just started laughing."

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.

"I'm super-shocked. What a moment. I didn't know what else to think, but 'wow,'" Grissom said.

Grissom was batting .324 with 14 homers, 67 RBIs and 27 stolen bases at Single- and Double-A this season. He started at second base and batted ninth for Atlanta. With family and friends in the Fenway Park stands, 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.

"I can't even put it into words," he said. "We've all really got me here to this point. So for them to be here, to watch it, it was one of the best things in my life."

Grissom added a single in the ninth. Since the home run ball was presumably lost, the Braves made sure to call for this one as a keepsake. He later scored on Dansby Swanson's single to make it 8-4.

"He did everything," Braves manager Brian Snitker said. "He did great. Nothing fazed him. That power is real."

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 RBIs and 12 stolen bases while shoring up the defense in center field. Harris moved up to the eighth spot in the order in the series finale, a showcase of Atlanta's organizational depth.

"It was like a 'We made it' moment, I guess," Grissom said. "Like, a 'We did it' type of feeling."

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 homer -- on five hits and two walks while striking out five. The last-place Red Sox lost their fourth straight game, and their sixth of seven.

The night, however, belonged to Grissom, who may have felt the nerves of a major league stage, but certainly didn't show it.

"He just seemed like a kid on the playground, pretty much just having a ball," Snitker said. "It's genuine. That guy just really likes to play baseball."

The Associated Press contributed to this report.