Indeed, the turning point came early, and it soured a start that Lance Lynn otherwise saw as a least a push in the right direction after a rough previous two.
Lynn opened the game with two quick groundouts before the Pirates began to find their way aboard. Singles by Andrew McCutchen and Garrett Jones extended the inning. Neil Walker followed with a walk.
Former No. 2 overall Draft pick Pedro Alvarez -- a threat to go deep. but also a candidate to strike out -- worked the count to 3-2 against Lynn. Lynn came back with a fastball, and Alvarez lasered it over the right-field wall for his second career grand slam.
"He knew a fastball coming and he won," Lynn said. "I got the first two guys out and then I loaded the bases. That's just bad pitching right there. You can't give that guy a chance to do anything in the first inning. I just didn't get it done in the first inning, and that cost us the whole game right off the bat."
That swing accounted for more runs than the Cardinals would score all afternoon. It also gave Alvarez back-to-back four-RBI games.
"He's a great pitcher, great competitor," Alvarez said of Lynn. "I faced him a few times, and I know he's not scared to throw any pitch any time. So I was just getting ready to hit."
Lynn settled in somewhat from there, shutting the Pirates out and allowing just three baserunners over the next three innings. He allowed another two runs in the fifth, which was his final inning. When the bullpen took over, St. Louis was staring at a deficit of four.
Insisting that fatigue and workload is playing no part in his sudden dip in effectiveness, Lynn has nonetheless labored in each of his last three starts. He's given up 17 runs in 15 1/3 innings during that span, which has swelled the right-hander's ERA from 2.42 to 3.62.
The trying stretch has probably taken Lynn out of the mix for an All-Star invitation, something he appeared to be closing in on not that long ago. And it will likely only augment internal discussions about whether a move to the bullpen makes sense for Lynn later in the season.
"He's going to continue to learn," Matheny said. "I don't think anybody thought he was just going to keep rolling through this league. You're going to have your bumps. It's how quick you adjust to them."
Eliminating the big innings is a critical place to start. He's allowed three or more runs in an inning three times over his last three starts. Lynn has also give up a pair of two-run innings.
"When it comes down to it and you give up four runs on one swing, it's a tough day," Lynn said. "I have that one inning where I give up a couple runs. If you do that, it's going to be hard to win a ballgame."
This offense has overcome larger deficits before, but Karstens hardly let them close.
The Cardinals scored twice off Karstens in the third on RBIs by Jon Jay and Matt Holliday. That was the only one of Karstens' seven innings in which St. Louis moved a runner into scoring position. He finished with seven strikeouts in the 95-pitch effort.
"With Lynn, he's not going to back down after four runs," Karstens said. "They're a very good hitting ball club, and my job was to minimize the damage."
St. Louis had a bit more success against a Pittsburgh bullpen that entered the day with the league's second-lowest ERA. Doubles by Jay and Carlos Beltran shaved one off the deficit in the eighth. The double was the 400th of Beltran's career.
He has driven in a run in eight straight games, which is both a franchise record and the best such streak in the Majors this year.
If there was a silver lining to be found on the afternoon it was the performance by the two recent bullpen additions. A 'pen that had been knocked around for seven earned runs the night before, was injected with new life on Saturday morning. Barret Browning and Maikel Cleto arrived from Triple-A, and both responded with scoreless appearances.
Cleto struck out three in an inning. Browning punctuated his Major League debut by retiring all six batters he faced.
"It can't get any better," Browning said. "After almost seven years in the Minors Leagues, fighting, clawing, trying to get somebody's attention, and then it comes. To be able to do what I did today was an unbelievable feeling."
Though the Cardinals are ensured a series loss, a win on Sunday would at least prevent the Pirates from claiming their first three-game sweep in St. Louis since May 1991.