PITTSBURGH -- Rarely in baseball do plans go the way they’re drawn up. The Nationals learned that hard truth again Tuesday, as the Pirates rallied in the eighth to come from behind and beat Washington, 4-1, at PNC Park.

“This game is weird,” Nationals manager Dave Martinez said.

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For a number of reasons, things turned weird. Pittsburgh starter Chris Archer was pulled after just one inning with right shoulder discomfort, pitting a formidable Nats offense against effectively a bullpen day for the Bucs. Whereas Stephen Strasburg handed the ball off to the bullpen with plenty of rested options after seven scoreless innings.

Yet with one swing of the bat, everything unfurled, highlighting Washington's surprising inability to score and the command issues of two of the team’s best setup options.

“We had a well-rested bullpen, and we just couldn’t close it out,” Martinez said. “It’s just weird how … It’s baseball. It’s baseball. We score [62] runs in five games, and then today we couldn’t get any runs but one.”

Strasburg tossed an effective start with little spectacle to it, notching only six strikeouts with few flashy plays to back it. His changeup drew eight swings and misses -- one shy of his season high -- against a struggling Pirates order, which had scored only one run in 34 innings before the eighth inning.

But Martinez decided to turn to his bullpen with Strasburg at 94 pitches; he’d thrown more than 100 in eight of his prior 10 starts. Martinez said he had Wander Suero “penciled in for the lefties,” and lefties Melky Cabrera and Adam Frazier were due up second and third in the inning.

However, Suero, who has allowed just two runs in his last 13 appearances before Tuesday, couldn’t get past leadoff batter Jacob Stallings -- a righty -- who roped a single. Cabrera drew a walk on a cutter low and away, a pitch that Suero said was moving differently than usual.

“Normally, my cutter moves more sideways, laterally, and it’s short,” Suero said through an interpreter. “Today, it had a lot of depth to it, and it was a lot bigger [arc] than normal.”

Arguably the weirdest part of Tuesday’s game came in the next at-bat, when Frazier tried to exploit Suero with a bunt to move runners into scoring position. Instead of playing down into an easily fieldable sacrifice bunt as intended, it took a line-drive trajectory between first and second base, and no National was prepared for it.

“I don’t think he tried to bunt it like that,” Martinez said, “but I don’t think he could’ve bunted it any better.”

With the bases loaded the Nationals turned to Daniel Hudson, who has drawn closing considerations with Sean Doolittle on the injured list. He’d allowed one run in 10 appearances (8 1/3 innings) since his acquisition from the Blue Jays at the Trade Deadline. But he quickly allowed a sac fly to Bryan Reynolds to tie the game, then threw what he called “probably the worst” fastball he’s thrown with the Nats to Starling Marte.

“I was trying to go in, and just kind of yanked it back over the middle of the plate,” Hudson said. “Pretty much middle-middle, and he smoked it.”

It landed in the right-center-field seats and, all of a sudden, a team that seemed unstoppable in the past week found itself down by three with three outs to work with against one of the top closers in the game, Felipe Vázquez.

It was a familiar situation to games early in the season, when Washington's bullpen couldn’t find consistency in the eighth inning. Tuesday’s loss was the seventh this season in which the Nationals led after seven innings, the second-worst mark in the National League behind the Cubs (nine).

The third-best record in the NL is no respite for a hungry Nats team, which fell to six games back of the Braves on Tuesday. Martinez knows that one-run games need to be won down the stretch to take the divisional crown, and he knows that no matter how weirdly things can fall apart, there are no excuses to be made for losses.

“It’s going to be a fight all the way ‘til the end,” he said. “We know that.”