Yet with two outs in the bottom of the ninth, it was Campana's single up the middle that sent home Martin Prado with the game-winning run, and the D-backs walked off with a 4-3 win over the Brewers.
The win snapped the D-backs' two-game losing streak and gives them a chance to split the series with the Brewers.
"I think that was the softest ball [Campana] hit all night," starter Wade Miley said. "He hit the ball hard all night and couldn't get a hit, and hits a nubber through the middle and wins the game."
Prado started the winning rally with a one-out double to left-center and moved to third when David Peralta grounded out to first.
That brought up Campana.
"Martin's at third, so I knew all I had to do was find a way to put a ball in play and beat it to first," the speedy Campana said. "So just getting a ball in play, hitting it on the ground [was key], because hitting it in the air pretty good wasn't working."
Campana grounded a Brandon Kintzler pitch to the right of second base and just out of the reach of a diving Rickie Weeks as Prado crossed the plate.
"It actually couldn't have worked out better to have him up there, just because we had a guy on third base who [with] just his wheels kind of pressures [the other team], makes them come in and cheat in," manager Kirk Gibson said. "One of the things we encourage [Campana] to do is try to get the ball on the ground. They all play in so far on him, if he puts the ball on the ground, he's got a great opportunity to have success, get on base. He hit a couple of balls to center field in the air. It just can't be his game. So it was good to see him do that. Obviously, it's big for us to get the win."
After watching leads evaporate in the first two games of the series, the D-backs had to feel like this one was déjà vu.
Arizona built a three-run lead against Milwaukee starter Matt Garza, capitalizing on some sloppy defense to score a pair of runs in the first inning and adding one in the third on an RBI single by Paul Goldschmidt.
The lead, though, would not last long.
Miley cruised through the first few innings before hitting a speed bump in the fourth.
Jonathan Lucroy and Carlos Gomez led off the fourth with singles, and after Miley fanned Aramis Ramirez, Khris Davis hit a first-pitch fastball over the wall in right-center to tie the score at 3.
"I felt like I made a pretty good pitch [on the Davis homer]," Miley said. "I've just got to be a little smarter in that situation with a guy like that. I felt like I located the ball well, moved it in and out and was able to throw sliders down and for strikes."
Miley was trying to go down and in with Davis in order to get him to hit the ball on the ground for a double play, but the mistake he made was throwing a pitch in the strike zone to a batter the D-backs know is aggressive.
"He's got a nice slider that he buried, and we chased it some," said Brewers manager Ron Roenicke, who watched his team strike out eight times against Miley. "But he locates well, and as long as you can get those pitches inside, you're going to be tough to hit."
After the homer, Miley settled in once again, but he ran out of gas after striking out the first two batters in the eighth, walking Lucroy and Gomez.
Gibson brought in Brad Ziegler, who the previous night had given up a game-winning grand slam to Lucroy. This time Ziegler fanned three of the four hitters he faced to keep the score tied until Campana's heroics in the ninth.