ST. LOUIS — Coming off a series in Phoenix in which the Cubs won two of three games against the Diamondbacks and hoped to turn their season around, they had an inning to forget in their 8-3 loss in the series opener Monday against the Cardinals.
Right-hander Alec Mills seemed to be rolling along, but his night came to a screeching halt when his defense didn’t help him out in the fourth inning.
Mills started the inning by striking out Matt Carpenter, but things quickly got out of control. He did what he wanted to do to the next batter, Dylan Carlson, getting him to roll over and hit a ground ball. But normally sure-handed third baseman Patrick Wisdom threw the ball high, pulling first baseman Anthony Rizzo off the bag and allowing Carlson to reach on the error.
‘‘It’s super-frustrating,’’ Wisdom said. ‘‘It kind of started with me. I’ve gotta make a better throw. It just kind of snowballed from there. We just didn’t make the plays when we needed to.’’
Mills allowed the next two batters to reach — on a base hit by Yadier Molina and a walk to Tommy Edman — to load the bases before Paul DeJong chopped a grounder in front of shortstop Javy Baez. The ball kicked off the heel of Baez’s glove as he was attempting to make a do-or-die play, leading to a run that made it 2-0 and keeping the bases loaded.
The ball found Baez again on another grounder on the next play, this one by Harrison Bader. Baez fielded the ball and fired to the plate in an effort to get the force. But the throw sailed over the head of catcher Willson Contreras, allowing another run to score and giving the Cardinals a 3-0 lead.
‘‘I hadn’t seen a game like that in a while,’’ manager David Ross said. ‘‘I know how Javy started off a little bit slow at short, but I feel like he’s been really making some spectacular plays of late.
‘‘I don’t feel like we’ve done that a lot lately. I feel like those [errors] were really uncharacteristic of this group as of late, for sure.’’
Mills was finally able to get the second out by striking out pitcher Jake Woodford, but he then walked Carlson to force in another run.
The Cubs’ last faux pas of the inning came on a slow grounder by Paul Goldschmidt between Mills and Rizzo. After initially hesitating on the play, Mills couldn’t get to first base in time to get the out. The Cardinals scored another run on the play to make it 5-0.
‘‘Defense has been great for me all year,’’ Mills said. ‘‘Just bad luck that it happened two or three times in the same inning.’’
The Cardinals hit only one ball out of the infield in the inning and scored four runs. It was the last inning Mills would pitch. He was charged with five runs (one earned) and five hits, with six strikeouts and two walks.
‘‘I’m proud of the way [Mills] pitched, to be honest with you,’’ Ross said. ‘‘I thought he was throwing the ball phenomenally. A lot of soft contact, the ball is finding holes, weird things happening, mistakes happening behind him. He kept his poise and continued to make pitches. I thought he was exceptional tonight.’’
The rest of the night was almost as bad, with the Cardinals getting home runs from Carlson and Goldschmidt against right-hander Keegan Thompson in the sixth to open an 8-1 lead.
‘‘I feel like we’ve been pretty good out there in terms of defense,’’ said Wisdom, who provided the Cubs’ only real offensive highlight of the game with a homer in the seventh. ‘‘That one just kind of got away from us.’’