PITTSBURGH — Jack Flaherty always had the tools. Figuring out how to put them together has been the challenge for the 23-year-old pitcher since the former first-round pick arrived in St. Louis two years ago.

While Flaherty is sketchy on specifics about what what exactly he changed heading into the All-Star break, one thing is for certain: the roadblocks — mental, physical and otherwise — are all gone. Flaherty is rolling, and so are the Cardinals.

Flaherty overwhelmed the Pittsburgh Pirates in a 2-0 victory on Sunday, striking out 10 against five hits and a walk over eight electric innings to keep up a dazzling run that has turned him into the de facto ace for the NL Central leaders. Flaherty (10-7) won for the sixth time in eight starts while dropping his post All-Star break ERA to 0.76 as St. Louis pushed its lead in the division to 4 1/2 games over second-place Chicago with three weeks to go in the regular season.

Carlos Martinez worked a perfect ninth for his 19th save to finish off a season series dominated by the Cardinals. St. Louis won 14 of its 19 meetings with Pittsburgh, including 10 of 12 in the second half, one of the main reasons the Cardinals are heading to October while the Pirates are planning for next season.

Paul Goldschmidt had an RBI double , and Harrison Bader added a run-scoring single off Pittsburgh rookie James Marvel (0-1). Matt Carpenter went 2 for 3 while starting at third base and is hitting .400 (6 for 15) in September as the veteran tries to shake out of a season-long slump.

Flaherty’s effectiveness ended Pittsburgh manager Clint Hurdle and second baseman Adam Frazier’s respective days a little bit early. Both were ejected by home-plate umpire Roberto Ortiz in the seventh for arguing balls and strikes after Ortiz ruled a pair of borderline pitches in favor of Flaherty.

“He’s taken it to another level,” Hurdle said of Flaherty. ” He was as advertised from what we watched coming in here. It’s been going on for two months.”

Marvel, the 1,087th player chosen in the 2015 draft, was solid in his first major-league start after piling up 16 victories across Double-A and Triple-A this season. With more than 40 people in the stands who roared every time he stepped out of the dugout onto the field at PNC Park, Marvel gave up two runs and four hits in five-plus innings with two walks and two strikeouts.