MILWAUKEE -- Jeff Locke put up some more zeroes for Pittsburgh.
Locke (5-1)allowed three hits in six scoreless innings and struck out a season-high seven, after seven shutout innings against Houston.
"You're seeing him grow up before your eyes," Pirates manager Clint Hurdle said.
Hurdle said he was most impressed with the fact that Locke did not have his best stuff against the Brewers, but still held the potent lineup scoreless with his inside fastball. It was Locke's fourth straight win and he has allowed three or fewer earned runs in each of his past seven starts.
"To be able to maneuver through that lineup without his best stuff is something," Hurdle said. "He is getting a little better every day. This has to be a big boost to his confidence."
Locke credited a sixth-inning double play started by Pirates third baseman Pedro Alvarez as one of the keys to his success Saturday.
"I was attacking them today and trying to stay efficient," he said. "It's nice to come into this ballpark and win a game. We've had some trouble here in the past."
The Pirates won for a second time in Milwaukee this season, but for only the ninth time since 2007 at Miller Park -- against 47 losses.
Brewers centerfielder Carlos Gomez, who hit two home runs after Locke had left the game, said he was very impressed with the pitcher.
"That kid has good stuff. He doesn't miss many pitches," Gomez said. "You have to tip your hat to the good job he did today. That kid is going to be one that people talk a lot about in the future."
Alvarez hit two long home runs to right field, prompting Hurdle to say he hoped the performance would boost Alvarez to go on a hot streak.
"I'm trying to keep it simple and put a good swing on the ball," Alvarez said. "We just want to go out and compete and if we do that, I know that we'll be successful."
"When I fell behind, they made me pay," Fiers said.
Milwaukee is 5-17 in May and has not won back-to-back games since April 29-30 at home against Pittsburgh.
The Pirates grabbed a 1-0 lead in the first inning as McCutchen hit his seventh home run. It was McCutchen's fourth home run off Fiers during his career and his third straight at-bat against Fiers in which he hit a home run.
Pittsburgh increased its lead to 3-0 in the second inning on a two-run shot by Alvarez and Walker hit a solo homer in the fourth.
Gomez hit his seventh home run of the year leading off the seventh inning off Pirates reliever Justin Wilson to cut Pittsburgh's lead to 4-1.
Alvarez added his 10th leading off the ninth inning, a towering shot to the top of the second level in right field.
Gomez hit his second home run of the game in the ninth inning to trim the lead to 5-2. It was Gomez's first career multi-home run game.
Brewers closer Jim Henderson was to see a doctor Saturday and will be out "a while," Brewers manager Ron Roenicke said. Henderson injured his right hamstring Friday while delivering a pitch that led to the second out in the ninth inning. He gave way to Francisco Rodriguez who earned a save in the Brewers' 2-1 win ... Pirates infielder John McDonald who was put on the 15-day disabled list May 15 with a lower back strain, will begin a minor league rehab assignment Monday at Triple A Indianapolis ... Brewers RHP Yovani Gallardo (3-4) will face Pirates LHP Wandy Rodriguez (5-2) in the series finale Sunday.