Chicago, IL – Matt Garza pitched his second complete game of 1, in game series Wednesday afternoon.
Garza (9-10) allowed an unearned run, six hits and a walk while earning the eighth complete game of his career.
He threw 123 pitches, including 88 for strikes, as Chicago won two out of three against Milwaukee to finish the home part of their 2011 schedule with a 39-42 record.
They are headed on a six-game road trip to St. Louis and San Diego to close the season.
Marlon Byrd hit a three-run homer in the win.
The Brewers scored their only run on a Starlin Castro error in the third inning and watched their lead for first place in the NL Central fall to 4 1/2 games over the Cardinals, who rallied to beat the New York Mets Wednesday night. Milwaukee's magic number to secure its first division title since 1982 is three.
Randy Wolf (13-10) took the loss after giving up six runs on 10 hits in six innings, falling to 2-1 in his last four starts.
Milwaukee returns home to wrap up its remaining six games against Florida and Pittsburgh.
"We love playing at Miller Park, it's no secret," said Milwaukee's Jerry Hairston. "So hopefully we play good baseball and clinch (a playoff berth) there."
Castro's throwing error allowed Yuniesky Betancourt to score from second base, but the Cubs shortstop also closed in on history, going 2-for-3 with an RBI to reach 199 hits for the season.
The 21-year-old is trying to become the youngest player in franchise history to reach the 200-hit milestone, and also the first Cubs shortstop to do it. He would be only the fifth MLB players since 1940 to get 200 hits at 21 years old or younger.
Castro has reached base safely in 34 straight games, tying Woody English's 1929 record for Cubs shortstops. He is the first Cubs player to have a streak that long since Jerome Walton's 43-gamer in 1989.
He tried to stretch his leadoff double in the first inning into a triple, but was thrown out at third base by left fielder Ryan Braun. Fans stood for Castro's last at bat in the eighth inning, but he walked on five pitches.
Castro, who was hoping to get No. 200 at home in front of his family and fans, looked at a 3-0 strike during the plate appearance.
"I wanted to [swing] but he told me to take it," said Castro. "Because the game's not even close, maybe if I swing at that pitch the next pitch is at my neck."
Garza's complete game was delayed twice in the ninth inning -- first on Hairston's two-out single, and then when D.J. LeMahieu dropped Betancourt's pop up behind the pitcher's mound.
But the 27-year-old righty fanned George Kottaras with a 77 mph breaking ball on his 123rd pitch, moving to 3-0 in his last five starts.
"There's no way I was coming out of this thing," said Garza. "It's a six-run lead. I'll give up five (runs) before I come out."
The Cubs tied the game at 1-1 on Castro's RBI single in the bottom of the third inning and took a 3-1 lead on LeMahieu's two-run double in the fifth. Byrd belted his ninth homer of the season in the sixth to make it 6-1 and Geovany Soto had an RBI double off Kameron Loe in the seventh.
The Cubs reached 3 million fans at Wrigley Field for the eighth season in a row, getting to 3,017,966 with Wednesday's game. They are the only pro sports team in Chicago ever to reach the 3 million attendance number and should be one of just four teams who have hit the plateau in each of the last eight seasons (the Yankees already have, while the Cardinals and Angels are on pace)...The youngest Cubs players to reach 200 hits are Billy Herman (206 hits in 1932) and Augie Galan (203 hits in 1935) at the age of 23...The Brewers were 4-2 on a six-game road trip and went 39-42 away from home this season...The Cubs went 4-2 on a six-game homestand.