Anthony Rendon gets eaten up by this fifth inning ground ball as the Nationals’ second-half swoon continues. (Patrick McDermott/Getty Images)

The Washington Nationals’ serial neglect of Stephen Strasburg and the spectacular futility of their offense collided Wednesday night, ugliness piled atop more ugliness. Their second-half spiral already had included a plunge in the standings, the firing of a hitting coach and the desperate search for a silver lining. It could not get any worse, and then it did.

Strasburg committed one mistake in eight luminous innings, dragging his teammates toward an opportunity to snap their skid. They kicked and screamed in a 4-2 loss to the Pittsburgh Pirates, another in a string of daily nadirs, an expansion of their capacity for dispiriting defeats. Fans fled Nationals Park during a three-run ninth-inning implosion. The ones who stayed witnessed a blown call that cost the Nationals a chance to come back.

Make it six losses in a row, longer than any slide they endured in 2012. Make it 11 in their past 13 games, a span during which they have scored 32 runs, including three in two games under new hitting coach Rick Schu. Make it 48 wins against 53 losses during a season fraying at the seams.

“When things get tough . . . your true colors really come out,” Strasburg said. “It’s all about what type of person you are. Are you the type that’s going to sit there and look in the mirror and do everything you can to be better out there? Or are you going to start pointing fingers? I don’t think there’s a single guy in the clubhouse who’s going to start pointing fingers. Every single guy in here is responsible, and we all want to win just as bad as any other team out there.”

They stand nine games behind the Atlanta Braves in the National League East, the largest deficit they’ve faced this season. They turned Wednesday to their ace to halt their free-fall. He gave them 12 strikeouts and allowed one run in eight innings. His offense kneecapped him, allowing left-hander Francisco Liriano to flirt with a no-hit bid.

The Post Sports Live crew debates whether the Nationals can still make it to the postseason, despite the hole they have dug themselves. (Post Sports Live)

“We want to win,” Strasburg said. “I don’t really care about the whole wins and losses as a pitcher. We need to win some games. It’s getting to the point where our backs are against the wall, so we’ve got to do what it takes.”

Jayson Werth provided brief hope in the ninth inning with a pride-preserving, two-run homer off Justin Wilson, his fifth home run in four games. It may have amounted to something more if not for Drew Storen’s latest misadventure in the top of the inning, when he yielded three runs, two hits and a walk while recording two outs. After Manager Davey Johnson came to take the ball, Storen stared past him, not saying a word.

“He has to concentrate a little bit more,” catcher Wilson Ramos said. “For me, he has to do that. Got a good arm, got good stuff. He just needs to go out there and get confidence.”

Johnson was asked whether Storen, whose ERA grew to 5.40, may head to the minors once Ryan Mattheus is activated. He hesitated and said, “There’s not a lot of better options.”

Werth’s blast to the right-center field seats only led to another dollop of frustration. Ramos ripped a one-out single to center off Mark Melancon. As Denard Span walked to the plate, Steve Lombardozzi stood on deck. Bryce Harper lurked in the dugout, resting his sore right knee. Johnson planned to pinch-hit with Harper only after Lombardozzi batted, ensuring Harper would end the game, win or lose, and avoid playing the field.

It never got to that point. Span bounced to second baseman Neil Walker. He fielded the ball and lunged to tag Ramos on his way to second. Second base umpire Laz Diaz pointed at Ramos — a tag. Walker flipped to first — the game.

Or was it?

The Post Sports Live crew debates whether the Nationals firing hitting coach Rick Eckstein will make any difference for the team’s disappointing offense. (Post Sports Live)

“Nope,” Ramos said. “Not even close. He told me, ‘He tagged you. I didn’t hear it, but I saw it.’ I said, ‘You didn’t see anything.’ Not even close. Maybe he want to go home.”

Replays proved Ramos correct — Walker would have needed Inspector Gadget’s arm to tag out Ramos.

“It was not even close,” Span said. “It’s too bad Laz missed it.”

Ramos barked at Diaz. Nationals lined up on the top step and leaned over the railing, hollering for a changed call.

“It’s almost a guess play,” Johnson said. “You’re assuming he was tagged.”

A Nationals public relations official declined to make Diaz available for comment, citing MLB protocol.

The Nationals’ protest stirred no change, of course. And as Span said, “That wasn’t the story of the game tonight.” The story was this: Strasburg became the first pitcher since 1900 to pitch at least eight innings, strike out 12 batters, walk none, allow two hits or fewer and not win.

Strasburg surrendered just a solo home run that Pedro Alvarez lined over the right-center field wall in the second inning. His start gave him 47 strikeouts in his career against the Pirates over just 28 innings in four starts. He pitched eight full innings for the third time in his career, and in nine of his past 15 starts he has gone at least seven.

“I want to be the big dog in the rotation,” Strasburg said. “That comes with the territory. Six innings isn’t cool anymore for me. I want to go seven, eight and hopefully nine some time.”

His one mistake came on a 96-mph fastball over the plate’s heart. Alvarez belted it. The ball hissed with the trajectory of a Kansas relief map, staying about 20 feet above the ground until it screamed into the front row over the high wall.

Liriano was even stingier. Anthony Rendon gave the Nationals their first hit with two outs in the sixth, a two-hopper to third that Alvarez stopped with a dive but couldn’t corral. He struck out eight and allowed two hits over 72 / 3 innings.

“They’ve got the best pitching staff in the league,” Johnson said. “So you can boo-hoo the hitters, but they’ve been doing it to a lot of people.”