ST. LOUIS -- With runners on first and second, two outs and holding onto a one-run lead in the fourth inning on Friday night, Jack Flaherty reached back and whizzed a 95-mph fastball past Pirates third baseman Colin Moran for a swinging third strike.

Flaherty walked off the mound expecting a roar from 40,000 fans at Busch Stadium. Instead, the Cardinals right-hander looked up at empty red seats and heard the piped-in crowd noise serving as a substitute at the ballpark. That’s when it hit Flaherty that he was pitching on an Opening Day unlike any before.

“It was weird, it was different,” Flaherty said after St. Louis' 5-4 victory. “Managing your emotions is different. I knew it was a big spot, important spot, big punchout, and it was weird. It was a completely different feeling. It was weird. But other than that, the juices were flowing, it was Opening Day, get a new team in there. Just go out there and compete.”

Flaherty and the Cardinals opened the 60-game regular season with a victory. But it was strange and different, with no Clydesdales or Cardinals Hall of Famers trotting around the ballpark to a cheering sea of red.

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Pregame introductions were quiet, with the occasional player tipping his cap or waving to the empty park. A few photographers were scattered along the first deck of seats. President of baseball operations John Mozeliak sat in the same seat he sat in for lunch almost every day during the four-month break from games in the sixth row of section 245. He was the only person in the upper deck.

Fredbird moved around the stadium without much to do. After Tyler O’Neill hit the Cardinals' first home run of the season, a solo shot in the third inning, the mascot went over to the Homers for Health sign in left field and changed the number to one.

It had been 284 days since Flaherty pitched in a game that counted -- dating back to his start in Game 3 of last year's National League Championship Series -- but the 24-year-old looked as though he hadn’t skipped a beat.

“It seems like forever ago,” Flaherty said. “It definitely feels like a long time competing against someone else.”

Flaherty cruised through six efficient innings on 62 pitches, and he completed seven with only two runs allowed on six hits. He hadn't allowed a run through six, which extended his scoreless innings streak to 25 dating back to last season, breaking his previous career-best mark of 23, set from July 26-Aug. 13, 2019.

Flaherty struck out six, working quickly by inducing groundouts and, as manager Mike Shildt says, “letting the defense play.” The Pirates had four singles in a span of five at-bats in the seventh -- including Jacob Stallings' two-run knock -- but Flaherty preserved a 3-2 lead by getting Jarrod Dyson to ground out to end the inning.

“Strikeouts come when they come, and you take the outs when you get them,” Flaherty said. “If they come quick, they come quick and you get some efficient innings. And when you get into big spots, like whatever inning it was with Moran, and you get into big spots in the seventh, you've got plenty in the tank.”

Flaherty had a dominant second half last season, posting a 0.91 ERA after the All-Star break and finishing fourth in NL Cy Young Award voting. He’ll likely be in that race again this year, and with Friday’s outing, it's clear why.

“I think I told [catcher] John Ryan Murphy during the game that this is a guy, when you watch him live, you realize how good he is,” Pirates manager Derek Shelton said. “You watch him on video and think he’s good, then when you watch him live, you realize why he’s pitching Opening Day for them.”

The Cardinals debuted their new-look lineup that features Kolten Wong at leadoff and Paul DeJong in the cleanup spot. DeJong provided a pair of key insurance runs with a 402-foot homer in the eighth inning. Left-handed closer Kwang Hyun Kim allowed two runs in the ninth before inducing a game-ending double play to notch the save , becoming the first St. Louis pitcher to earn a save in his MLB debut since Brad Thompson in 2005.

Right fielder Dexter Fowler also homered, hitting a solo shot off Pirates starter Joe Musgrove in the fifth.

“When we talk about the depth of the lineup, we really felt like pretty much the whole lineup had a lot of quality at-bats all the way through,” Shildt said. “That’s what elite offenses do, have quality at-bats all the way.”