Thus ended the Reds six-game winning streak. And with the Chicago Cubs losing, the Reds had a chance to move to within 3 1/2 games of first place.
But they muffed it and also fell 3 1/2 games behind the third-place St. Louis Cardinals.
The Reds scored three runs after they had two outs in the first inning. Jesse Winker opened the game with a single and with two outs Derek Dietrich tripled into the right field corner for a run.
Yasie Puig then ignited another cross county home run deep into the left field seats and there was that daily 3-0 lead.
With Castillo, that’s usually as safe as a cub with momma bear. Not on this day.
The indication that it wouldn’t be Castillo’s day surfaced early. Milwaukee leadoff batter Yasmani Grandal began the bottom of the first with a home run.
Christian Yelich walked and Mike Moustakas doubled to put runners on third and second with no outs. Castillo walked Lorenzo Cain to fill the bases.
Castillo finally recorded an out, striking out Eric Thames. Then came disaster from an unlikely source — surehanded and accurate-throwing shortstop Jose Iglesias.
Orlando Arcia chopped one in the grass next to the pitcher’s mound. Iglesias charged it and bobbled it. He should have put the ball in his back pocket. Instead he threw wildly on the run as two runs scored. He was charged with two errors, one on the bobble and one on the throw for the two runs. Another run scored when Travis Shaw grounded out and the Brewers led, 4-3.
The Reds tied it in the third when slump-bitten Eugenio Suarez homered with one out and it was 4-4.
Castillo, though, couldn’t keep it there. It began with another walk, this to No. 9 hitter Ben Gamel. Grandal, the former No. 1 Reds draft pick, struck again, doubling home Gamel.
Castillo continued his lack of command and control by throwing a wild pitch that sent Grandal to second. With two outs, Cain singled to right field to score Grandal and it was 6-4.
That was the end for Castillo. He pitched 3 2/3 innings and gave ups six runs, five hits and walked five, using up 96 pitches to record only 11 outs.
The Reds drew within one run in the fifth when Chacin walked Jesse Winker, Joey Votto doubled and Winker scored as Suarez grounded out.
The inning continued when Dietrich was hit by a pitch, the sixth time in the three-game series, an ouchy and black-and-blue record — the most times hit by a pitch in a series. And there is one game left.
But from that juncture it was a duel of bullpens and it was a standoff. Both ‘pens turned off the spigots.
On the Cincinnati side, Michael Lorenzen, Robert Stephenson, Amir Garrett, Jared Hughes and David Hernandez combined to hold the Brewers to no runs and no hits over the last 4 1/3 innings.
The Brewers matched that pitch-for-pitch. Alex Claudio, Matt Albers, Adrian Houser and Josh Hader combined to hold the Reds to no runs and no hits over the last 3 1/3 innings.
The last 13 Reds went down in order with Hader pitching the last two innings and striking out four of the six he faced, two in each inning.