Corey Hart belted a game-tying two run blast in the ninth and added a game-winning RBI single in the 13th inning as the Brewers defeated the Cubs, 8-7, in the opener of a three-game series at Miller Park on Friday.
Rickie Weeks and Ryan Braun were each hit by a pitch from Lendy Castillo (0-1) to start the bottom of the 13th inning before Aramis Ramirez singled into right to load the bases with no outs.
"Castillo hit the first two guys so you knew our chances weren't good after that," said Cubs manager Dale Sveum.
Hart then slapped a single up the middle for his fourth hit of the night, scoring Weeks from third to give the Brewers their ninth straight home victory over the Cubs.
Vinnie Chulk (1-0) got the victory after tossing two scoreless innings in relief. Hart and Jonathan Lucroy each knocked in three runs as Milwaukee won its second contest in three tries.
"It was an interesting ball game," said Brewers manager Ron Roenicke. "I didn't know what was going to happen. A lot of weird things."
David DeJesus smacked a grand slam and added an RBI triple while Alfonso Soriano added two hits and an RBI, but the Cubs dropped their second in their last three.
The Brewers scored a run in the first on a double-play ground out from Ramirez, and carried a 1-0 lead until the seventh when Darwin Barney ripped a one-out triple into the right-field corner and reliever Jose Veras plunked pinch-hitter Ian Stewart and walked Reed Johnson to load the bases.
Cameron Loe then entered for Veras and pinch-hitter DeJesus launched his first offering over the wall in left field to give the Cubs a three-run edge.
But Milwaukee answered with four in the home seventh -- all with two outs -- to take a 5-4 lead. Braun worked a walk and quickly scored on Ramirez's double off the wall in right-center field.
Hart then singled and George Kottaras walked before Lucroy cleared the bases with a double into the right-field corner to give Milwaukee a one-run lead.
Milwaukee held a 5-4 lead in the ninth with closer John Axford on the mound looking for his 50th consecutive save.
Stewart started the ninth by reaching first on a throwing error from Ramirez and DeJesus plated Stewart two batters later with a triple into center field to tie the game.
Axford then got Starlin Castro swinging at strike three, but the ball got away from Lucroy behind the plate, allowing DeJesus to race home from third and Castro to reach first to provide the Cubs with a one-run edge. An RBI single from Soriano scored Castro to make it a 7-5 contest.
The Brewers answered with two in the bottom half to send the game to extra innings as Ramirez worked a one-out walk and Hart launched the tenth pitch of his at-bat into the seats in left to send the game into extras.
Chicago starter Matt Garza allowed one run on three hits with five walks over five innings...Milwaukee starter Randy Wolf pitched six scoreless innings and surrendered four hits and three walks with five strikeouts...Cubs first baseman Bryan LaHair has now reached base safely in 28 straight games after receiving an intentional walk in the 13th inning...Axford's blown save was his first in the regular season since April 18, 2011 at Philadelphia.