PITTSBURGH -- Having been in the Cardinals' system since being selected by St. Louis in the first round of the 2019 MLB Draft, Zack Thompson has watched dozens of starts by Adam Wainwright, and he’s had even more in-depth conversations about pitching with the franchise fixture.

But Wainwright is not the MLB pitcher who the left-handed Thompson has studied the most as he’s worked to carve out a big league career.

“Clayton Kershaw has left a pretty good blueprint for a fastball/curveball/slider lefty, and I’m just trying to follow his lead,” Thompson said. “I’d say I’ve watched more Kershaw than any other pitcher in baseball.”

The 25-year-old Thompson put on his best impersonation of the Dodgers' superstar left-hander on Wednesday at PNC Park, limiting the Pirates to two runs on six hits and one walk over five innings as the Cardinals won, 6-4, to avoid going 0-6 in Pittsburgh for the 2023 season.

With the win, the Cards improved to 1-5 in Pittsburgh and avoided their third winless season in Steel City in the franchise’s rich history.

In Thompson’s three career starts before Wednesday -- one in 2022 and two this season -- the Cardinals had were unable to score a run of support while the lefty was still in the game. In Wednesday’s start, Thompson had a 3-0 lead before taking the mound thanks to an RBI single from Paul Goldschmidt and a two-run double by Richie Palacios in the first inning.

Thompson kept the Pirates off balance and guessing for five innings by using 47 four-seam fastballs (one topped out at 97.4 mph) and 25 pitches that Thompson calls his slider, but Statcast refers to as a cutter. Call it what you want, but it was a highly effective pitch for Thompson that elicited 11 swings and five swings and misses.

“He used the fastball well at the bottom and top of the zone and was able to reach back with some 96s and 97s when he needed to,” Cardinals manager Oliver Marmol said. “The [slider/cutter] didn’t land as much as he’d like, but he got a decent amount of swing and miss. His mix was good.”

Thompson scouted Kershaw's pitching repertoire to try to figure out ways to complement the fastball/curveball mix that he leaned on heavily while in a relief role earlier in his career. As a starter, he’s more of a four-pitch pitcher, and the slider/cutter has become one of his favorite pitches to throw.

“I’d argue that right now it’s my most comfortable pitch and I’ve commanded it the best,” Thompson said. “It just gives the batter a funky look and a different look. Kershaw has shown that that’s a good mix, and he likes to lean heavily on his slider. So, I’ve taken a page out of his book.”

Debate has raged for years inside Cardinals circles as to the best way to use Thompson, be it as a starter or a high-leverage reliever. After the Minor Leagues were shut down in 2020 because of COVID-19, the Cardinals aggressively promoted Thompson to Triple-A in 2021, and he struggled mightily as a starter. In addition to going 2-10 primarily as a starter, Thompson allowed 18 home runs and had a 7.06 ERA.

Thompson’s first MLB shot came in 2022, and it was in a relief role. This season, he made the Opening Day roster as a reliever after not allowing a run in Spring Training. He went his first eight outings of the regular season without surrendering an earned run. However, after three shaky outings and seeing his walk rate spike, the Cardinals not only demoted Thompson, but they also moved him back into a starting role. Largely because of his troubles landing his offspeed pitches and his adjustments to the automated ball-strike system, Thompson once again fell on hard times as a starter.

Asked recently what he sees himself as going forward, Thompson playfully responded, “as a pitcher,” before flashing a big smile. However, it’s the starting role that he covets most. His thinking there was more influenced by the sage experience of Wainwright instead of Kershaw.

“Growing up, all the way through college and early in pro ball, I was [almost] always a starter,” said Thompson, who owns a signed Kershaw jersey. “Then, I came up last year with an opportunity out of the bullpen, and I feel like that taught me a lot, especially at this level.

“Talking with [Wainwright] the other day in the outfield [during batting practice], he told me about how guys used to come up and pitch out of the bullpen and learn how to pitch in those big spots. Then, you start to piece it together as a starter. That’s the plan for myself moving forward. If all else fails, I know I can compete out of the bullpen if needed.”