PHOENIX -- The D-backs flirted with danger for the second straight game, and this time they paid the price as the Nationals scored three runs in the ninth for a 9-8 win over the D-backs on Sunday afternoon at Chase Field.

On Saturday, Arizona allowed five runs in the ninth but rallied for two in the bottom half of the inning before a walk-off walk sealed the win over the Nationals.  

While the ninth inning Sunday will get the most attention, an argument could be made that the D-backs never should have let the game stay that close heading into the final frame.

Arizona had opportunities in the sixth and seventh innings to really put the game out of reach, but couldn't take advantage.

Over those two frames, the D-backs drew seven walks, but they managed to score just one run despite having 10 batters reach base. The patience that allowed them to put the runners on seemed to abandon them when they put guys in scoring position.

“I don’t think we were particularly patient with men at third base and less than two outs,” D-backs manager Torey Lovullo said. “We could have broken the game open. We had some overanxious hitters. The quality of at-bats were good enough. You walk 10, 11 times, you’re doing a good job of surveying the strike zone. We’ve just got to finalize things and capitalize on it. We just did a lot right. But it just wasn’t a complete game offensively. We’ve got to get better.”

After scoring a run in the seventh, the D-backs led 8-5 and were on the verge of a three-game sweep, which would have been their first of the year.

That Nationals, though, weren’t about to go away.

“You got to give the Nats credit,” D-backs first baseman Christian Walker said. “They kept fighting. They made it tough, yesterday's game too. It was it was a battle. They fight all the way to the end and you’ve got to be willing to do the same. It's just one of those things, it's not going to go your way every time.”

By the time the ninth rolled around, the D-backs held an 8-6 lead with Miguel Castro coming on to close things out.

Castro has been one of Arizona’s best relievers so far this season, but things got away from him in a hurry.

Luis García led off with a double on the first pitch and Keibert Ruiz followed with a first-pitch single.

Joey Maneses took a pitch for a ball before depositing the next offering, a hanging slider, into the left-field seats.

Four pitches equaled three runs and a 9-8 lead.

Unlike Saturday, when the D-backs scored a pair of runs in the bottom of the ninth for the win, Hunter Harvey shut the door and picked up his first career save.

It made for a frustrated group of D-backs postgame, including Walker, who despite hitting a home run, lamented the fact that he left some runners on base as well.

“I left two guys on third with less than two outs,” Walker said. “You know, that's the difference in the game right there if you really want to get critical. I'm sure everybody feels a little bit of responsibility to some extent. [I] understand you're not going to cash in on every RBI opportunity, but as the four-hole hitter [I] take full accountability. I got to be able to get those runs in, that could be the difference in a game like you [saw] today.”