McCann hit a first-inning grand slam to quickly end a 24-inning scoreless streak, lifting the Braves to a 7-4 win over the Brewers on Sunday at Miller Park.
"We definitely needed it; we've been pretty flat the last couple of days," Dan Uggla said. "Zero runs in 18 innings [in Milwaukee]. Mac got us off to a great start."
The Braves managed only six hits in consecutive 2-0 losses to the Brewers on Friday and Saturday, and the team desperately wanted to score early on Sunday.
McCann made it happen, hitting a 94-mph fastball on a 2-1 pitch into the Brewers' bullpen for his 10th grand slam.
"It was big," McCann said. "To go to left-center -- usually in my career I don't hit the home runs that way. I'm working hard to stay on the ball, and luckily today I put a good enough swing on it to go that way."
The slam set the tone, and the Braves pounded 14 hits to win the final game of the series. Each of the eight starting position players reached base.
"Just to get a win today was huge," McCann said. "If you look back at our season we've had so far, we've run off some streaks. We've lost a couple in a row here, but all in all we're having a really good year. Sometimes we're going to go through stretches where we don't play great baseball, but that happens to every team in the league."
Braves manager Fredi Gonzalez said the home run was a big lift for a team that hadn't scored since Thursday.
""To get ahead and get four runs, and then tack on a couple more later on and win the game, it's big," Gonzalez said. "They say hitting is contagious. Hopefully it catches on with a couple of guys and keeps going."
Chris Johnson and Jordan Schafer also homered for Atlanta off Milwaukee starter Alfredo Figaro (1-2).
Paul Maholm (8-6) pitched five innings for Atlanta. Five relievers appeared in the final four innings, with Craig Kimbrel working the ninth for his 21st save in 24 chances.
"The offense was the big thing today," Maholm said. "I pitched well for four innings and then I gave up some runs. It's good for the team to leave here with a win, to go into an off day relaxed."
Schafer went 4-for-5 in the game and led off the first with a double down the right-field line. Andrelton Simmons then hit a bloop single, moving Schafer to third. Freddie Freeman walked to load the bases with one out.
Figaro struck out B.J. Upton for the second out, but McCann made sure the team scored by hitting his eighth homer this year and the team's fourth grand slam. McCann had been in a 1-for-16 slump his last six games.
Johnson hit his fifth homer in the second inning to make it 5-0, and Schafer hit his third homer in the fourth to extend the lead to 6-0.
Maholm cruised through the first four innings before struggling to complete the fifth. The Brewers scored four runs off the left-hander, capped by Jonathan Lucroy's two-run homer to pull Milwaukee to within 6-4.
"Unfortunately I let them back in it, but I think it's a good way to get us going and get us back to where we need to be," Maholm said.
Maholm allowed four runs on eight hits and a walk, while striking out three in five innings. It was just his fourth win in 15 decisions against Milwaukee in his career.
The Brewers loaded the bases with two outs in the seventh, but Jordan Walden was summoned and got Juan Francisco to pop up in foul territory behind home plate to end the inning.
Figaro lasted just 3 1/3 innings, giving up six runs on nine hits and three walks, while striking out four. The right-hander has given up 13 home runs over 53 1/3 innings.
"He was up in the zone with his fastball today and couldn't command his offspeed pitches," Milwaukee manager Ron Roenicke said. "Most of the offspeed pitches he did throw were up, and he can't pitch that way.
"If he's not throwing a lot of offspeed or at least enough to get them off the fastball, they know they only have one pitch to look for, and if he makes a mistake, they're going to hit it well."