SAN DIEGO -- Fresh off a wholly disappointing sweep in St. Louis, the Padres returned to Petco Park on Tuesday in unfamiliar territory: They no longer control their own playoff destiny.

With the National League Wild Card race out of their hands, all the Padres could do, said third baseman Manny Machado, was “win the next 13” and put as much pressure on the Cardinals as possible.

Machado -- who spoke passionately pregame about moving past his very public spat with Fernando Tatis Jr. -- did his part. He homered twice, and just missed a third. Tatis had two hits and an RBI as well. But those efforts went for naught, as the Padres’ playoff hopes continued to dwindle with a 6-5 loss to the Giants, replete with a brutal finish.

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The Cardinals, meanwhile, beat Milwaukee, meaning the Padres fell five games back in the race for the second Wild Card spot -- the furthest they’ve been from a playoff position all season.

“We’re at the point it’s do-or-die right now,” said right-hander Joe Musgrove. “We’ve got to try to win out. That’s the idea. The Cardinals are playing the best ball they’ve played all year long. … I’ve been on that side of a winning streak. You lose one game, and things could easily turn. So we’ve got to just keep doing our job, trying to win ballgames, let the rest of it figure itself out.”

Musgrove has been the Padres’ workhorse this season. He hasn’t missed a turn all year, and he’s been the steadiest presence in a rotation that has been thrown into disarray because of injuries. But Musgrove wasn’t at his best on Tuesday, allowing five runs over 5 2/3 innings, a rare rocky outing at a bad time for it.

The Padres’ offense backed him up, homering four times to match its total from the entirety of the 10-game road trip. Machado hit a pair of majestic blasts into the Western Metal Supply Co. building -- reaching the third level in the first inning and the second level in the third. Tommy Pham and Austin Nola also went deep, and Wil Myers robbed Steven Duggar of a go-ahead blast in the eighth, leaving the game tied entering the ninth.

And that’s when Tuesday’s game offered a couple twists that served as a microcosm of the way the NL West has tilted this season. Facing Padres closer Mark Melancon, the Major League leader in saves, the first-place Giants rallied to take the lead with three singles that all clocked in at exit velocities of 75 mph or lower.

“Mark didn’t beat himself,” said Padres manager Jayce Tingler. “There weren’t any walks. There were just quality pitches. They were able to stay inside the ball just enough to fist a couple through.”

Making matters worse, the Padres put two aboard in the bottom of the ninth inning for Machado, who lined a 112.3-mph rocket to the right side. It took one hop and kicked off the glove of first baseman Brandon Belt. But the ball popped into the air, eye-level for Belt. He coolly snared it and started a game-ending double play.

Beaten by half a step, Machado took three more strides up the first-base line, then exhaled, putting his hands on his thighs in anguish. The Padres have lost some tough games lately, but this one felt different. They didn’t play particularly poorly. They pounded out 13 hits. They slugged. They played solid defense. Their pitchers mostly made quality pitches.

They still lost.

“We play 27 outs, we leave it all out there, whatever happens, happens,” Machado had said prior to the game. “If we lose, we lose, but we know we left it all out there.”

Machado went and did exactly that; the loss stung just the same.

Still, Machado’s no-holds-barred effort to help salvage the Padres’ season did not go unnoticed.

“He’s a leader in every sense of the word,” said Musgrove. “His performance on the field is one thing. The amount of innings he plays in the field is impressive. I know that guy’s hurt. He’s banged up a little bit like a lot of guys are here. But he goes out every night, and he gives it everything he has.”

Some nights, like Tuesday, it isn’t enough.