The victory -- combined with the Cardinals' loss to the Cubs -- moved the Brewers into a tie for the National League Wild Card lead and second place in the NL Central. At 49-39, Milwaukee is now a season-high 10 games over .500.
"We know we are playing good baseball," said Bill Hall. "We can't worry about what anyone else is doing, especially with it being this early. We feel like we are rolling on all cylinders.
"Everybody has streaks. Hopefully, by the end of this homestand, we won't even want an All-Star break, we'll want to keep playing."
Both starting pitchers had poor outings, and the hitters on both teams were able to capitalize.
Hardy led the way for the Brewers, reaching base four times, clubbing two home runs and driving in four. It seemed as if the shortstop could do no wrong at the plate.
"I can't explain it," Hardy said. "It feels good. I think I'm just relaxed and comfortable up there, and it seems like I'm getting a lot of pitches to hit.
"When things are going bad, it seems like you hit the ball hard and everything gets caught. When things are going good, it seems like you don't have to hit the ball hard because they'll find holes."
Hardy has been as hot as anyone in the National League over the last three weeks. He is coming off a recent 16-game hitting streak, during which he hit .448, and he has hit six homers in his last six games.
"He's good, but that's an understatement," manager Ned Yost said. "He's been very, very good. He's right on everything, hitting for power, hitting doubles, hitting singles and clutch hitting.
"He's hitting everything. I don't know how much better it gets than right now, for any player. It really doesn't get much better than the way he's swinging right now."
Hall had three run-scoring hits -- going 3-for-5 with two doubles and a single -- to continue his hot series. The Pirates started three left-handers over the weekend, and he took full advantage of the opportunity to play every day.
"It was a lot of fun," Hall said. "I knew I was going to be in there for three days in a row. There were some guys I've been successful against. Going into the series, I was starting to feel confident with my swing again and starting to feel good at the plate."
Neither Brewers starter Jeff Suppan nor Pirates starter Zach Duke made it past the third inning, both allowing six runs before being pulled.
The Brewers jumped out to an early 4-0 lead when Hardy and Ryan Braun hit back-to-back homers and Hall added a run-scoring single in the first inning. But the Pirates came right back and scored four runs of their own off Suppan in the top of the second.
Both teams scored two more runs in the third inning, chasing Suppan and Duke from the game. Mitch Stetter (2-1) threw two innings in relief and earned the win for the Brewers.
The bullpen was brilliant in this game, throwing six scoreless innings after Suppan was ineffective early on. Stetter and David Riske each worked two innings, with Guillermo Mota and Brian Shouse taking care of the last two.
Yost credited Dave Bush's eight-inning performance from Saturday night as a big factor in Sunday's game.
"The bullpen was great today," Yost said. "Our bullpen was completely rested, so we could take a chance without our long guy to be able to try to piece it together. The bullpen did a tremendous job, they shut it down and allowed us to climb back in it."
Milwaukee took control of the game in the decisive fourth inning against Pittsburgh reliever Denny Bautista. The Brewers sent nine men to the plate, Hardy hit his second home run of the game and the team pushed across four runs to run the score to 10-6.
The Brewers offense set a team record with 12 extra-base hits in a nine-inning game and tied a team record with nine doubles. The team notched 12 extra-base hits once before, during a 10-inning game in 2001.
"Today was a good offensive day for the whole team," Hardy said. "Everyone kind of feeds off of one another. If our pitchers are throwing good, it seems like everyone's throwing good, and if our hitters are hitting, it seems like everyone hits."
Sunday was most certainly an offensive day. Suppan just didn't have his best stuff, but the club was still able to come away with a win.
"Every start is different," Suppan said. "It's about evaluating your stuff when you go out and pitch and pitching with what you have [working] that day. Lately, I haven't been pitching well with the stuff that I've had."
His final line on Sunday was six earned runs on five hits, two walks and two home runs allowed. Suppan, who is 4-6 on the season, saw his ERA go up by nearly a half-run to 4.71 with the poor performance.
He has now pitched poorly in his last four outings, allowing 18 earned runs and 20 hits in just 15 2/3 innings.
"You have to be able to identify whether your sinker has been moving well or offspeed stuff or whatever," Suppan said. "I think I just need to do a better job of evaluating my stuff while I'm pitching to be more effective during the game."
"It goes in cycles," Yost said. "Whether you are a hitter or you are a pitcher, everybody goes through it."