PITTSBURGH – After his last time out against the Guardians, Mitch Keller voiced some disappointment that he felt great for his start, but it didn’t translate into results. On Saturday, he bounced back nicely from his recent second-half hiccups to record six strong innings.

However, it wasn’t enough to survive another ninth-inning collapse. Aroldis Chapman allowed four runs with two outs in the ninth, and the Pirates would end up losing to the Nationals at PNC Park on Saturday night, 8-6, after also dropping the first half of their split doubleheader, 5-3.

This is the second straight year that Keller excelled in the first half of the season, but hit some road bumps in the second half. That was mostly in a poor West Coast road trip in mid-August during which he allowed 15 runs over his two starts against the Dodgers and Padres, but he had also given up three earned runs in each of his last two outings, failing to record a quality start in either.

This time, though, Keller looked as sharp as he had been all season, striking out eight with no walks while allowing just two runs. It was the ninth time this season Keller pitched at least five innings with no walks allowed, the most for any Pirates starter since Iván Nova in 2018.

“Obviously, I wish we won the game,” Keller said, “but yeah, feels good to put it all together.”

Arsenal-wise, Keller pitched off of his four-seamer, getting four of his strikeouts with it, but also used his spin pitches to keep the Nationals off balance.

“[Yasmani Grandal] had a really good gameplan back there of just using all my spin, just mixing,” Keller said. “Trying to keep them off balance as best as possible. We're trying to be unpredictable and just use my weapons as a positive and use my ability to spin the ball as a strength.”

Aided by a snag by third baseman Jared Triolo to his left with a couple runners on base in the sixth, Keller was able to pitch out of his biggest jam of the night and exit with a 4-2 lead. Triolo also had a pair of early RBIs with a two-out, two-run single in the first inning.

The bullpen couldn’t close it for Keller, though. It started in the seventh, when Andrés Chaparro caught up with a Ryan Borucki sinker for a game-tying two-run shot. Isiah Kiner-Falefa singled home a go-ahead run in the eighth as the Pirates again took a two-run lead into the ninth, and they came inches away from closing it. With two outs and two on, pinch-hitter Ildemaro Vargas looped a ball into shallow right that Connor Joe appeared to have in his glove, but he couldn’t hang onto it as he hit the ground, and it turned into a go-ahead double.

Pirates manager Derek Shelton didn’t see the game hinging just on whether or not Joe could make the diving catch, though.

“Earlier in the game we had situations to score and add on and we didn't,” Shelton said. “You can't look at a guy making a diving catch -- if he makes it, I agree that it's a situation where the game is over and it's a great catch. But there were other opportunities in the game that we didn't capitalize on."

Borucki and Chapman accounted for the 27th and 28th blown saves of the Pirates’ season, the most in the National League. Since the save became an official stat in 1969, only the 2022 Pirates (28) and 1985 Pirates (31) have blown 28 or more saves in franchise history. There’s been a dire need for consistency from the back end of the bullpen, and they haven’t gotten it.

“It's definitely frustrating,” Shelton said. “We've gotta figure out the answer to it because it seems too often that we're one strike away, one pitch away, definitely one out away from getting out of it, and we've not done it."