The home run, which was Byrd's 11th of the season, came in his second at-bat since the June 2 injury, and gave the Reds a lead they'd never surrender. Marlins starting pitcher Dan Haren surrendered the home run to Byrd, who finished 1-for-4.
"He was able to stay on a ball out over the plate," Reds manager Bryan Price said. "[Haren] was kind of back and forth with the sinker-cutter mix, and [Byrd] was able to stay on one that got up out over the plate and he was able to handle it out to right-center."
The Reds optioned right-hander Donovan Hand to Triple-A Louisville to make room for Byrd on the active roster.
Byrd went 2-for-7 with a homer over two rehab games with Double-A Pensacola, the second of which was cut short when Thursday's contest was suspended in the fourth inning due to malfunctioning lights.
"Swinging in the cage, it's not the game speed, so once you get the game speed down, that's when you know," Byrd said prior to Friday night's game.
Byrd is hitting .213/.286/.456 with 11 homers and 26 RBIs over 48 games in his first season with the Reds.
"The DL is no fun, it's no fun," Byrd said. "You're around and watching the team, you love when they win but the losses you want to be out there trying to make them win, so it's nice to be back out there."
Robert Bondy is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.