HOUSTON — The Alex Bregman swing that ended Saturday night’s game and sent a raucous sellout crowd at Minute Maid Park home happy was the devastating knockout blow by an Astros team that methodically landed effective jabs in the previous three innings, working its way back into the contest against the Dodgers.

There was the sixth inning, when the Astros pieced together six singles to score four runs. There was a tremendous diving catch by Chas McCormick in right field in the seventh, followed by clutch RBI singles by Jeremy Peña and Jon Singleton in the eighth to complete Houston’s comeback from five runs down.

With the Dodgers wobbling and with their backs to the wall, Bregman took a mighty swing on the second pitch reliever Blake Treinen threw in the ninth inning and launched it high over the left-field wall for a dramatic walk-off homer that sent the Astros to a 7-6 win.

“You always kind of go back in the season and think about big moments, big wins, big games, and this is one of those that you will reflect on,” Astros manager Joe Espada said. “The atmosphere feels like a playoff atmosphere. We know we’re playing a really good team like the Dodgers. Our bullpen giving us a chance there, big at-bats off the bench, big hits and how this team stays collected and unified and able to come through, it’s impressive.”

The win was arguably the best of the season for the surging Astros, who came back from a 5-0 deficit to win a game for the second time this year. They were 6-for-10 with runners in scoring position and had only two extra-base hits — Bregman’s homer and a triple in the eighth by catcher Yainer Diaz (3-for-4).

The Astros took the series from the Dodgers and improved to 48-30 since April 27, an extended run that has enabled them to overcome a 7-19 start and take over first place in the American League West.

“I think the guys have done a great job of coming in here and competing,” Bregman said. “We knew they’ve got a great team over there. We just try and focus on the next pitch and continue to play hard.”

Treinen had struck out Jose Altuve swinging on three pitches to end the eighth and strand the bases loaded, with the Astros blowing a huge chance to take the lead. Josh Hader worked a 1-2-3 ninth before Bregman turned on a Treinen sinker and launched it a Statcast-projected 407 feet for his fourth career walk-off hit (and second walk-off homer).

“Trying to get something over the plate to be able to put a ball in the air,” he said. “Obviously, he’s a really good reliever. He’s been one for a very long time. Just trying to get something I could get a swing on, and I was fortunate enough to do that.”

As the crowd at Minute Maid Park erupted, Bregman was mobbed by his teammates at home plate and had his No. 2 jersey ripped off his back.

“It was awesome,” Bregman said. “Just to see the happiness on everybody’s face in the dugout was awesome. I kind of blacked out.”

Peña called it “beautiful.”

“We know we can come through in big situations, and we did that tonight,” he said.

Trailing 5-0, the Astros sent nine batters to the plate in the sixth and scored four runs on six singles, chasing Dodgers rookie left-hander Justin Wrobleski from the game after 5 2/3 innings. Diaz, Peña, Jake Meyers and pinch-hitter Victor Caratini had RBI singles to cut the lead to 5-4.

“We were halfway through the game and still had a lot of game to play and nobody was going to go up there and give away at-bats,” Diaz said. “In the D.R. [Dominican Republic], we have a phrase, it says ‘Union brings power.’ We were just playing united.”

Cavan Biggio, the son of Astros legend Craig Biggio, hit a solo homer in the eighth off Tayler Scott to make it 6-4, but the Astros tied it by scoring twice in the bottom of the inning on RBI singles by Peña and Singleton. The Dodgers’ five-run lead was gone, but the Astros’ biggest blow was yet to come.

“It was a little punch in the gut, but we’re going to fight through it and the guys did,” Espada said. “We got those runs in the eighth and kind of gave us a chance there.”