Two multi-base gaffes allowed the Brewers to snap starter A.J. Burnett's career-best winning streak at nine, although Burnett (10-3) was sharp in six of his seven innings. Andrew McCutchen's hot streak continued with a home run in his fourth straight game to spot his team a 1-0 lead, but it all came unglued in the sixth.
Milwaukee's Nyjer Morgan singled up the middle and Ryan Braun served a ball to right field, where outfielder Garrett Jones returned a throw over the cutoff man and all the way to the tarp beyond the third-base line, allowing Morgan to score and Braun to reach third.
"Those are plays we have to make," Pirates manager Clint Hurdle said. "If we get the ball in, it's first and third, who knows, we [could] roll a double play. The way [Burnett] negotiated innings prior to that with people on base pitching out of the stretch ... we maybe could have won the game. He pitched a very, very good ballgame."
Braun came home one batter later when Aramis Ramirez singled up the middle, and the Brewers took a 2-1 lead. It went to 3-1 when Rickie Weeks hit a sharp bouncer that eluded Pedro Alvarez at third base and bounded into the corner for another error -- later changed to a hit. Weeks scored when Martin Maldonado hit a cue shot double down the right-field line, making it 4-1.
"That's probably the best stuff I've had in a long time," Burnett said. "I tried to minimize the damage the best I could, but a couple runs in the sixth, that's the ballgame."
The Pirates avoided additional heartburn in the sixth when Walker stayed in the game after a stealing Ramirez collided with Walker's left forearm. Walker flagged down an errant throw and received attention from the training staff before returning to action.
Over his 15-game hitting streak, Walker has hit 27-for-59 (.458) with eight doubles, 14 RBIs and 18 runs.
Facing Milwaukee starter Yovani Gallardo (8-6), the Pirates struck out 14 times over seven innings and finished with 17 strikeouts on the day for a two-day total of 32 and series total of 44. Pittsburgh previously struck out a franchise-record 17 times in a game twice -- in 1995 and 1997.
The 14 K's were a career-best mark for Gallardo. McCutchen, at least, proved immune, as he was the only starter not to fan. He produced an opposite-field shot against Gallardo leading off the fourth, and became the first Pirates player to homer in four straight games since Garrett Jones in July of 2009.
"That home run was a pretty good pitch on the outside part of the plate, but it stayed up a little bit, enough to where he was able to reach it," Gallardo said. "He's on fire right now. He's a good hitter. He seems like he's on everything, and you've just got to challenge him, go at him and see what happens."
McCutchen can become the first Pittsburgh player to go deep in five straight games since Jose Castillo in May of 2006 when the Pirates visit the Rockies on Monday.
"He's as good a player as there is in the league right now," Hurdle said. "He's playing at an elite level across the board. He's earned his name being in those [Most Valuable Player] conversations at this point. He's got a lot of ground to cover, and the longer he stays in this thing if he keeps playing well, the more notoriety that will come his way."
McCutchen finished 3-for-4. In six games against the Brewers this year, McCutchen has gone 12-for-24 with four homers and nine RBIs. In his last 12 games, he's been unstoppable, going 28-for-50 (.560) with two doubles, a triple, seven homers and 16 RBIs.
"He's the best player in the league right now," Walker said. "I've played with the guy since 2006, and this is as good as I've ever seen him go. He's seeing the ball, driving the ball, opposite field ... it's eerie the similarities in terms of where they hit the ball with Braun, the success he's had. You could see Andrew going that course."
The Pirates (49-39) momentarily dropped a half-game behind Cincinnati for first place in the National League Central, with the Reds facing St. Louis on Sunday night.