The Cardinals were well aware of what the Padres’ momentum swings could do before their National League Wild Card Series started. That’s why the strategy was to go on the offensive early, throw their best pitching at the Padres’ homer-happy lineup and hope that would take the momentum out of the home dugout at Petco Park this week.

Game 2 didn’t quite work out that way. Fernando Tatis Jr. and Wil Myers each hit two home runs -- all four coming in the sixth inning or later -- as San Diego staved off elimination with an 11-9 win over the Cardinals and forced a decisive Game 3 on Friday.

Jack Flaherty will be on the mound for the Cardinals against, well, the Padres haven’t figured that out yet.

“That’s our guy,” said Kolten Wong, who led St. Louis’ offense Thursday with a homer and four RBIs. “That’s our hammer. There’s nobody else you’d rather have on the mound than Jack.”

• Box score

The Cardinals jumped out to an early lead for the second time in as many days against the Padres’ pitching staff and held a 6-2 lead in the sixth inning. With as many baserunners as the Padres had stranded so far (eight), the Cardinals looked like they were cruising to a sweep. Key defensive plays had largely deflated the Padres’ offense, and despite starter Adam Wainwright leaving the game with the bases loaded in the fourth, the Cardinals still had a two-run lead at the end of four.

It was sabotaged by walks. Back-to-back free passes in the fourth gave the Padres their second run of the night, and the game started to get away from the Cardinals when lefty Génesis Cabrera walked the first two batters in the sixth. Cabrera then struck out Trent Grisham swinging for the first out. Giovanny Gallegos came in to face Tatis and Manny Machado.

“You’ve got to attack, you’ve got to make pitches,” Wainwright said. “When you do that, when you execute what your game plan is, and you execute your pitches, they get out. Those guys are normal hitters. They’re very talented. But they all have holes, and they all have ways you can exploit their swings. You just gotta make pitches. Several times I didn’t do it, and then several times after me, guys didn’t do it either.”

Tatis and Machado quickly showed the force that they have been this season. Tatis -- who had struck out with runners on twice earlier Thursday, after striking out against Gallegos in Game 1 -- launched a slider over the plate into left field to bring the Padres within one. Then Machado worked a full count before mashing a home run into left-center field to tie the game.

Momentum was on the Padres’ side.

“With Tatis, I don’t really have that mindset of feeling anxious whether runners are on base or not,” Gallegos said through interpreter Antonio Mujica. “Yesterday when I came in and I faced him, I was the winner in that fight ... and today, he won. All you got to do is tip your cap and show up tomorrow ready to win a ballgame.”

The Padres weren’t done. In the bottom of the seventh, Wil Myers yanked his own home run that hit the warehouse in left field, and Tatis hit his second homer of the night -- this one a two-run shot to right off Daniel Ponce de Leon -- complete with an epic bat flip.

“It’s a good lineup. No secret to it,” manager Mike Shildt said. “They’re kind of a momentum team. Once the momentum started, we weren’t able to have any shutdown innings. ... We had a little bit of a hiccup with our pitching, which is just that. A hiccup. Hiccups don’t last long.”

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The Cardinals got two back in the eighth with two sacrifice flies, but Myers launched his second home run of the game in the bottom of the inning off Kodi Whitley in his postseason debut. That home run was the difference in the score after Paul Goldschmidt homered off Padres closer Trevor Rosenthal to lead off the ninth.

The way the Cardinals fought back after each Padres home run is an approach they will take into Friday, when they’ll likely face a slew of relievers they’ve already seen in this series.

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St. Louis hopes that momentum is on its side.

“Usually when someone punches you in the mouth like they did -- sixth, seventh, eighth, it’s one of those where it’s hard to come back from,” Wong said. “You saw this team fight back every single inning. … We’re swinging the bats well. We’re doing what we need to do to stay in games, compete, win. We’re just ready for tomorrow. Obviously getting off the field, it stung knowing that we weren’t going to win that game, but everyone’s up and everyone’s ready to go.”