Tanner Roark has pitched to a 0.82 ERA while striking out 20 batters and walking one over his last three starts. (Brad Mills/USA Today Sports)

A few minutes before Kelvin Herrera jogged in from the Washington Nationals’ bullpen to save what would eventually become a 2-1 win over the Cincinnati Reds, the out-of-town scoreboard at Nationals Park brought the kind of news the Nationals must train themselves to handle these days. The Atlanta Braves and Philadelphia Phillies, the teams ahead of Washington in the National League East, had just taken leads in their games. A loss would have dropped the Nationals to seven games out of first place. They cannot afford to slip further.

Herrera had thrown 29 pitches about 17 hours earlier and had not looked particularly comfortable in the process. He later admitted he was tired Sunday, that he had to go to unusual effort to stay ready and to maintain his command. But after he was handed the lead Tanner Roark preserved with seven innings of one-run ball, the one Ryan Madson held with a perfect and dominant eighth, Herrera did not want to concede it.

He got his first two outs easily, without the kind of line-drive fireworks that have defined his outings lately. Then came Reds star Joey Votto, one of the more decorated and eclectic offensive talents of his generation.

Herrera got two strikes on him, at which point he faced a decision.

Given the opportunity to pinch-hit for catcher Matt Wieters with two outs in a rally a half-inning earlier, Nationals Manager Dave Martinez opted to let Wieters hit for himself — a decision that backfired when Wieters popped out. But Martinez said later he couldn’t pull Wieters from a close game like that. Wieters had homered earlier, his first home run since April 29, but that wasn’t the reason Martinez stuck with him over available pinch hitters Ryan Zimmerman and Mark Reynolds.

“I would never take Wieters out when we’re ahead like that because he’s got the feel of the game,” Martinez said. “He’s watched these hitters all game, and for me, we needed him that last inning.”

Herrera asked Wieters how he thought they should handle Votto, particularly with two strikes. Wieters suggested change-ups away. Staying down and away meant limiting Votto’s ability to hit a game-tying homer.

“They’re going to have to string some hits together,” said Wieters, explaining his limit-the-damage thought process later. Herrera agreed, knowing Votto is susceptible to off-speed stuff away. Votto took the first change-up for a ball. He took the second for strike three, a pitch that sealed the Nationals’ first one-run win since July 12. They have won five of six games since deciding to stand pat at the trade deadline. They have won eight of 11 overall.

That so much calculation went into one batter, that so much planning and effort was required to secure one of the 27 outs the Nationals needed Sunday, sums up their situation perfectly. As they have finally started to win consistently, Philadelphia and Atlanta have not given them an inch. They have not made any major gains in their division. They sit six games back of the Phillies and 4½ behind the Braves, who hold the second NL wild-card spot as they travel to Washington to begin a four-game series beginning with a doubleheader Tuesday. These games matter, and so does the state in which the Nationals enter them — as strong and consistent as they have been all season.

“We’re going to go out there and we’re going to keep playing like we’ve been playing and just keep playing team baseball,” Roark said. “Getting guys over when we need to get over and putting the ball in play and pitching to our strengths and doing everything as a team that we know we can do.”

Roark’s resurgence — he has a 0.82 ERA while striking out 20 batters and walking one over his past three starts — has been among the keys to this team’s consistency. His first masterpiece of the season, an eight-inning gem in Milwaukee two turns ago, began this run of eight wins in 11 games.

Around that time, Bryce Harper seemed to find his swing. His opposite-field double, part of another two-hit day Sunday, combined with Wieters’s solo homer to give Roark a two-run lead. Harper is 13 for 29 (.448) with eight RBI and seven walks in his past nine games. His batting average at the all-star break was .214. It is now .234.

Roark nearly conceded that lead in the fourth when four straight singles scored a run and left him in a bases-loaded jam with nobody out. Wieters reminded him to stick with his game plan, that those hits were not hit well, that he wasn’t suddenly relapsing into his midsummer struggles. Roark got three straight outs to end the rally. The Reds never rallied again.

In fairness, the Nationals’ entire recent run has come against losing teams, meaning their surge likely will face more resistance when the Braves arrive. So much has gone into building this run in the first place, so much energy and effort and planning into every pitch — let alone every win.

To continue it against clubs like the Braves, then the Chicago Cubs, then the St. Louis Cardinals, and so on, will take a lot of successful little moments like the one Herrera orchestrated Sunday. Who knows if it will matter in hindsight, if the Nationals have enough left to keep pushing. But after Sunday, and one of the more encouraging weeks of a discouraging season, they look as capable of making that push as they have in months.