David Bote celebrates his walk-off grand slam Sunday night. (Jon Durr/Getty Images)

With one swing of the bat late Sunday night, Cubs pinch hitter David Bote turned a 3-0, series-clinching win for the Nationals into a crushing, 4-3 Washington loss. Bote’s grand slam off Ryan Madson was the first walk-off grand slam to erase a 3-0 deficit since Sammy Byrd of the Reds did it against the Pirates on May 23, 1936.

For the Nationals, it was another brutal defeat in a season full of them, and a missed opportunity to make up ground in the National League East.

“We left here with one win,” Nationals Manager Dave Martinez said after watching his bullpen blow a late lead for the second time in three days. “We should have had three.”

Sunday’s loss counts the same as the Nationals’ 57 other Ls this season, but in the moments after Bote, with the Cubs down to their last strike, hit Madson’s 2-2 fastball 442 feet into the Chicago night, it felt like it meant more.

Sunday’s loss was among the worst regular season defeats in Nationals history, perhaps second only to an 8-7 loss to the Mets on Sept. 8, 2015. Washington entered that game at Nationals Park in similar position, trailing New York by five games in the National League East. The Nationals rocked Mets starter Matt Harvey for seven earned runs in 5 1/3 innings and took a 7-1 lead into the seventh inning.

With two outs and a man on first base, the bullpen needed only seven outs to even the series and set up an important rubber game. Blake Treinen walked David Wright and allowed a run-scoring single to Wilmer Flores. Felipe Rivero replaced Treinen and promptly walked Juan Uribe and Curtis Granderson to force in another run. With the score 7-3, Manager Matt Williams called upon Drew Storen, who allowed a bases-clearing double to Yoenis Cespedes that cut Washington’s lead to 7-6. Storen wasn’t done sinking the Nationals’ playoff hopes: He then walked Daniel Murphy, David Wright and Lucas Duda in succession to tie the score. Mets outfielder Kirk Nieuwenhuis provided the decisive run in the eighth inning with a solo home run off Jonathan Papelbon.

“It’s a tough one,” Papelbon said in a near-silent clubhouse after the game. “A tough pill to swallow.”

On the MASN postgame show, distraught analyst Ray Knight described that 2015 loss as the third-toughest in Nationals history, including the postseason. (As far as regular season games go, blowing a 9-0 lead against the Braves on July 20, 2012, is up there, but Washington would go on to win its first division title that year. There was also Washington’s 8-5, 12-inning loss to the Padres on Sept. 17, 2005, which included a game-tying grand slam by Khalil Greene with two outs in the ninth. The Nationals lost their next three games to fall out of the wild-card race.)

“The bullpen just imploded,” Knight said of the Nationals’ 8-7 loss to the Mets. “It didn’t matter who was out there; they couldn’t throw a strike. … We had two outs in the seventh inning before all that stuff started and, my goodness, we threw 30 balls and 13 strikes after the second out to [Travis] d’Arnaud. That’s almost … hard to compute, that you’ve got major league pitchers that cannot throw the ball over the plate the way that we had tonight.”

Wilson Ramos talks with Drew Storen after Storen walked in the tying run against the Mets on Sept. 8, 2015. (Alex Brandon/Associated Press)

The Nationals’ bullpen wasted a solid effort from Jordan Zimmermann that night. On Sunday, Madson’s meltdown spoiled Max Scherzer’s seven scoreless innings.

“It’s a gut punch,” Scherzer said. “It’s about how you respond to this.”

The Nationals begin a four-game series at St. Louis on Monday trailing the Braves and Phillies by 5.5 games. It’s a familiar position. Since July 1, Washington has been no fewer than five games and no more than seven games behind the NL East leader. There’s still time to make up ground, but not if the team doesn’t rebound immediately from Sunday’s loss.

The Nationals didn’t respond well to that loss to the Mets, blowing another late-inning lead to New York the following night. The Mets’ sweep left Washington seven games back. The Nationals lost their next two games, effectively sticking a fork in their season.

The results of the next week will help determine whether Nationals fans remember Bote’s walk-off grand slam as the unofficial end of Washington’s year, or an especially bad loss in a season full of them. Two months ago, the Nationals staged their own dramatic comeback on “Sunday Night Baseball,” overcoming a 6-2 deficit to beat the Phillies, 8-6. It was only one win, but like Sunday’s loss at Wrigley Field, it felt like it meant more, a much-needed spark that would turn around the season. Instead, the Nationals lost eight of their next nine games.

(Thanks to @eric_hobeck, who wondered where Sunday’s loss ranks among the worst nonelimination, regular season losses in D.C. sports history. This post has been updated.)

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