ST. LOUIS -- You don’t get this far into a pennant race without figuring out ways to keep going when the going gets treacherous.

The Padres, who landed in St. Louis trying to shake off a miserable month, may have suffered their cruelest loss of the season Saturday night at Busch Stadium. Despite seven masterful innings from Yu Darvish and what seemed to be just enough offense off St. Louis’s ageless ace, Adam Wainwright, the Padres found a way to lose ground, falling, 3-2, to the Cardinals on Tyler O’Neill’s eighth-inning home run.

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O’Neill’s two-run blast was more painful because it came with two outs, the Padres a strike away from going into the ninth inning with a lead.

The loss knocked San Diego to 2 1/2 games behind St. Louis for the second National League Wild Card spot with only 14 games remaining and a challenging schedule left to navigate.

“The good thing about baseball is we’re playing again tomorrow and we play every day,” Padres infielder Jake Cronenworth said. “It is a tough loss and a tough stretch of the season, but at the same time, whatever number of games we have left, we have to take day by day, play tomorrow like it’s the last game and the next after that like it’s our last.”

The Padres didn’t go into Saturday desperate for a win, not with more than two weeks of season remaining and the Wild Card race so close, but a loss would mean desperation lurked just around the corner. They admitted as much before the game.

“We need to get this one tonight, there’s no doubt about it,” manager Jayce Tingler said a couple of hours before first pitch. “This is a big game.”

For 7 2/3 innings, all was going according to plan. Darvish dominated over his seven innings, and the Padres jumped out to a two-run lead after a string of good at-bats in the fourth inning. But Emilio Pagán hung a cutter to O’Neill with two outs in the bottom of the eighth inning.

Darvish’s start -- sandwiched between those of recent additions Vince Velasquez and Jake Arrieta -- was the one the Padres had to have, and they knew it. For a time, Darvish reset the series tone. He dominated through the early innings, picking up seven strikeouts in a string of 10 batters starting in the third inning and ending in the sixth.

Darvish’s ability to get strikeouts came in handy in the fourth and sixth innings, when the Cardinals got the first two runners on. Darvish struck out the next two batters in both cases, all four of them going down looking.

It unraveled quickly for the Padres in the eighth. The Cardinals cut the 2-0 lead in half when Harrison Bader doubled and later scored on a sacrifice fly. Pagan walked Paul Goldschmidt to set up O’Neill’s heroics.