MILWAUKEE -- Coming into the game Wednesday night against the Baltimore Orioles, Milwaukee Brewers starting pitchers hadn't allowed a run in 13 innings, and Matt Garza wasn't about to let that streak end.

The veteran right-hander produced his most effective start of the season, holding Baltimore scoreless for 6 1/3 innings as Milwaukee completed a sweep with a 4-0 victory at Miller Park.

"We keep feeding off each other," said Garza (4-4), who scattered five hits and two walks while striking out four. "It has been a fun ride. We need to keep going and see how this thing plays out."

Garza worked out of a bases-loaded jam with nobody out in the third. He responded with two strikeouts and then escaped when Seth Smith flied out to left.

"It was a big momentum shift for us," Garza said. "It was awesome. I was able to sneak out of it. I got a couple of punchouts and a flyout. I really took off from there. I got my mechanics back in order in the third and I felt like I was in control from there on out."

He had put two more on in the third but cruised from there and retired 10 of his final 11 batters for his first victory in four starts and just his second victory in his last six decisions.

"He pitched with some traffic on in the first three innings, but I thought the last three and a third he pitched very, very well," Brewers manager Craig Counsell said.

Milwaukee's bats couldn't accomplish much against Baltimore left-hander Jayson Aquino but made the most of their limited opportunities.

Aquino (1-2) was making a spot start in place of Chris Tillman, who was placed on the paternity list after his wife gave birth the night before, and held Milwaukee to four runs (three earned) and five hits while striking out seven without a walk.

"(Aquino) pitched real well, he deserved a better fate," Orioles manager Buck Showalter said. "We didn't play well behind him defensively."

Travis Shaw put him in an early hole with a double to lead off the second inning and scored when Keon Broxton reached on an error by Manny Machado to give the Brewers a 1-0 lead.

Ryan Braun followed suit in the fourth, opening the inning with a double off the top of the wall in right and coming home on a one-out single by Domingo Santana to make it 2-0.

Broxton homered later in the inning, sending Aquino's first pitch over the wall in center for his 14th home run of the season.

"I miss(ed) a pitch and the result was a home run," Aquino said through a team interpreter. "I just missed a pitch right there."

Oliver Drake, Jared Hughes and Corey Knebel combined to allow three hits and strike out seven in the final 2 2/3 innings to complete Milwaukee's fourth shutout of the season and second in the last 10 games.

The victory helped National League Central-leading Milwaukee maintain a 3 1/2-game lead over the second-place Chicago Cubs, who they'll face Thursday in a makeup game at Wrigley Field before wrapping up the first half with a three-game series in New York against the Yankees.

"We are just going to keep riding it, man," Garza said. "There's not really much to say about it. We're going to just keep going and see if we can finish these last four games off strong to build a nice cushion before the break."

NOTES: The Orioles activated LHP Zach Britton (left forearm strain) from the 60-day disabled list. He worked a scoreless seventh inning, allowing a hit and a walk in his first action since May 4. ... Brewers 3B Eric Sogard will get one more day to rest his sore ankles before the team decides whether to place him on the disabled list, manager Craig Counsell said. ... Milwaukee RHP Wily Peralta began a minor league rehab assignment with Triple-A Colorado Springs. Peralta has been shelved since June 20 with a strained right calf and will pitch in two-inning stints as he continues his conversion into a reliever, Counsell said. ... The Brewers agreed to terms with prep OF Tristen Lutz, the No. 34 overall selection in last month's draft. Lutz will join the team's Arizona Rookie League squad in Phoenix later in the week.