LOS ANGELES – For eight innings, the Dodgers’ offense was looking for answers against D-backs ace Zac Gallen, who allowed just one run and struck out a career high 13 batters.

But once the Dodgers got to the D-backs bullpen, it was their time to pounce. Mookie Betts, who wasn’t in the starting lineup, delivered a walk-off single against Joe Mantiply to help the Dodgers take three of five over the D-backs with a 3-2 win on Thursday night at Dodger Stadium.

• Box score

“It was a great win, considering how well Gallen threw the baseball,” said Dodgers manager Dave Roberts. “I don’t think anyone was going to score runs off him tonight. He was in complete control, but we kind of hung in there, stayed in the ballgame and won late. It says a lot about the ballclub.”

Julio Urías didn’t have his best stuff, but the Mexican left-hander was able to keep the Dodgers in the game by allowing just one run over 5 1/3 innings. That helped the Dodgers wait out Gallen and ultimately get to the bullpen.

Cody Bellinger got the rally started in the ninth with a leadoff double that nearly carried into the front row of the bleachers. Freddie Freeman was intentionally walked with one out and Will Smith beat out an infield single. Max Muncy then had a swinging bunt go his way, beating a slow dribbler down the third-base line for another infield single.

Justin Turner struck out swinging for the second out, setting up the stage for Betts, who came off the bench to pinch-hit for lefty Joey Gallo. Betts worked a full count against Mantiply and then lined a single to left field, his first walk-off hit since joining the Dodgers.

“It’s cool,” Betts said. “Actually, I think that might be one of my first pinch-hit hits, so that part was pretty cool in itself. But we got a win and that’s all that really matters.”

It was the Dodgers’ 45th comeback win of the season, and the second in the rare five-game set against the D-backs. But one of the reasons they were in that situation was because of another shaky outing by closer Craig Kimbrel.

Kimbrel hit Jake McCarthy to lead off the ninth inning, but caught a break once McCarthy was thrown out at second base. That luck ran out quickly, however, as Christian Walker continued to torment the Dodgers with a go-ahead homer off a Kimbrel four-seam fastball.

Following a stretch of nine consecutive scoreless outings, Kimbrel’s stuff has started to dip over the last week. The veteran closer has now given up at least one run in three of his last four appearances. His season ERA is at 4.14.

“You can’t hit the leadoff hitter with a breaking ball,” Roberts said. “I think the stuff is starting to slide a little bit, fastball velocity. I’ve just got to continue to look at this. We’ve got to have our best guys at the back end.”

Over the course of the season, Roberts has stayed patient with the struggling Kimbrel. But with the postseason about two weeks away, the skipper has become more noncommittal as the organization’s focus has quickly shifted toward figuring out what the best plan is in October.

“This is a point in time where performance matters,” Roberts said. “We need our best.”

Evan Phillips has been the Dodgers’ best reliever this season, but he might be too valuable in his current role: Putting out fires in high-leverage situations. Brusdar Graterol returned from the injured list on Thursday and looked sharp, tossing a scoreless inning. He will be an option moving forward.

Blake Treinen suffered another setback following a sim game on Tuesday, making it unlikely he’ll be a high-leverage reliever down the stretch. Yency Almonte, who was a bright spot before going down with injury, started a rehab assignment, and the Dodgers hope to have him back soon.

If the Dodgers eventually decide to pull Kimbrel from his closer’s role, they’ll also need to figure out what his new role would be. Kimbrel struggled to find consistency in a setup role with the White Sox last season.

Luckily for the Dodgers, they won, and they’ll have a few weeks to answer these questions.

“Obviously the ninth inning is unlike any other,” Roberts said. “I do think that having guys that have finished games for us is a good thing. I’m just going to think through it and figure out what’s best for the ballclub.”