PHILADELPHIA — Matt Strahm knew it.

The Phillies lefty missed his spot. Catcher J.T. Realmuto was set up for a high-and-inside fastball. Instead, the pitch sat dead red near the letters and Strahm let out an expletive as the ball hit Masyn Winn’s barrel and carried over the left field fence.

Winn’s home run was the winning run in a 3-2 Phillies loss over the St. Louis Cardinals. It’s only the second time this season the Phillies (24-17) have lost a series opener at home. The hot Phillies offense struggled against left-handed starter Matthew Liberatore and righty reliever Kyle Leahy, who recorded a season-high seven outs.

Liberatore was lifted in the sixth inning with two on, one out and a run already in with Edmundo Sosa due up. With the righty Leahy coming in, Rob Thomson pulled off a “line change,” substituting all three of his right-handed hitters at the bottom of the lineup for lefties. Bryson Stott replaced Sosa, while Max Kepler came in for Weston Wilson. Brandon Marsh pinch hit for Johan Rojas an inning later. Stott and Kepler could not drive in the runs. All three left-handed pinch hitters combined to go 0-for-6 in the game. Stott matched up against former Phillie JoJo Romero and flew out in the eighth. Kepler and Marsh both struck out against Cardinals closer Ryan Helsley.

“I know that Helsely is pitching the ninth,” Thomson said. “We had the one bad matchup with Stott on Romero, but Stott hits lefties pretty well. I feel confident in his at-bats, but I felt like in the sixth inning, that was the time to go because we had some traffic. It just didn’t happen.”

The Phillies lineup combined for only one extra-base hit or fewer for the ninth time this season. They are now 3-7 this season against left-handed starting pitchers.

Cristopher Sánchez struggled with his command in the fourth and fifth inning, but was able to post his fourth quality start of the season. He allowed two earned runs, and walked three batters for a third consecutive outing. Sánchez walked three or more batters in an outing just six times all of last season.

The Cardinals have won nine games in a row. The Phillies will try to snap St. Louis’ long winning streak on Tuesday, weather permitting. Jesús Luzardo is scheduled to take the mound against Sonny Gray.