Votto, who is seeking to be 100 percent again after left knee surgery disrupted his 2012 season, returned in the third inning and hit Rob Wooten's first pitch for a two-run homer to left field and a 4-0 Reds lead.
"Votto got on the board," said Reds manager Dusty Baker. "We got good pitching. That was big. Guys threw the ball well. We played good defense. I forgot how to shake hands [after a win]. It seems like it's been a long time."
Reds starter Armando Galarraga, a non-roster pitcher in camp, pitched two scoreless innings with one hit allowed and two strikeouts. Reliever Sean Marshall followed with one scoreless inning with two hits and one strikeout. Jonathan Broxton was next with one perfect inning.
"Galarraga looked good," said Baker. "He kept the ball down and changed speeds. It looked like he was healthy again. When he was healthy he was tough. I only saw him a few times but it looked like he knew how to pitch."
Brewers starter Tyler Thornburg, who is trying to land a spot in the rotation this spring, gave up two runs and two hits with one walk over two innings.
"I think I threw four off-speed pitches," said Thornburg. "We were just trying to get the fastball location down. Now we can start working on the off-speed pitches, working on the put-away pitches. I have six more starts in Spring Training. I'll work up to those."
Milwaukee reached the scoreboard in the top of the sixth inning against reliever Curtis Partch. With one out, Taylor Green reached on a three-base error by center fielder Yorman Rodriguez. Next batter Khris Davis hit an RBI double to center field and scored on Scooter Gennett's RBI single to right field. Both runs scored against Partch were unearned.
Cincinnati got the run back in the bottom of the sixth, when Jason Donald scored on Devin Mesoraco's RBI fielder's choice as the ball was bobbled at second base for an error.
Up next: For the first time this spring, a member of the Reds rotation will get a start when Homer Bailey has his debut Tuesday vs. the Padres. First pitch is at 3:05 p.m. ET in Peoria, Ariz. Bailey will be opposed by Padres right-hander Anthony Bass. Second baseman Brandon Phillips, who did not play Monday, should be back in the lineup.
Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, and follow him on Twitter @m_sheldon. This story was not subject to the approval of Major League Baseball or its clubs.