Justin Turner’s solo homer in the eighth lifts the Dodgers to a 3-2 win over the Diamondbacks

Kenley Jansen made the sign of the cross as he exited the bullpen. At 9:31 p.m., in the moments before “California Love” reverberated through Dodger Stadium’s speakers, the congregants at the ballpark roused themselves for a revival. On the final day of one of the worst months of his career, Jansen jogged to the mound aiming to collect his first save in 25 days.

There was ample reason for alarm. Jansen had pitched four times since returning from the disabled list on Aug. 20 and had surrendered runs in all four appearances. The performance cracked the veneer of invincibility he had constructed during his time as the Dodgers’ closer.

And it left him, in the ninth inning of a 3-2 victory over Arizona, pitching like an angry Kenley, he said.

The Dodgers were ecstatic with the result. Aided by mechanical adjustments suggested by pitching coach Rick Honeycutt, Jansen flashed the movement and velocity he needed on his signature cut fastball. He pitched around a bloop double to keep the Diamondbacks off the board, reduce his team’s deficit in the National League West to one game and deliver a rebuke to anyone who questioned his readiness for the season’s final month.

“The atmosphere felt like the playoffs,” Jansen said. “The crowd helped too.”

The electricity crackled before Jansen reached the stage. Enrique Hernandez tied the score in the seventh inning with a pinch-hit home run off former Dodger Zack Greinke. An inning later, Justin Turner capitalized on an inexplicable gaffe by Arizona manager Torey Lovullo and a hanging slider from Greinke with a go-ahead solo homer.

One performance will not reduce all doubt surrounding Jansen, who struggled earlier in the year before missing time this month with a recurrence of his heart condition. But he came through at a critical time for his team. A loss would have extended Arizona’s division lead to three games. With two more victories this weekend, the Dodgers (73-62) can reclaim first place.

“We’ve got to win as many games as we can here down the stretch,” Turner said. “Especially when we’re playing the team that we’re trying to chase down.”

A night earlier, the Dodgers dropped the first game of this critical four-game set when Rich Hill surrendered a three-run homer and the offense struck out 15 times. The team appeared embarked on a sort of sequel on Friday, only with more hard contact and more frustration. Hyun-Jin Ryu delivered seven solid innings, but his line was marred by a first-inning home run.

Ryu dumped his team into a gully after three batters. He gave up a leadoff single to outfielder Steven Souza, who drilled a grounder to the left side of the infield. Manny Machado dived to smother the baseball, but Souza beat the throw.

Two batters later, Paul Goldschmidt stepped to the plate. Ryu fed him a 1-0 cutter. The pitch arrived on the outer half of the plate. Goldschmidt possessed enough strength to reach across the plate and drive the baseball into the right-field seats for a two-run shot.

“That was on the black, maybe a little high — but Goldy is one of the best players in the game,” manager Dave Roberts said.

The offense squandered an early chance to cut into Arizona’s lead. Cody Bellinger sprayed a double into left field to lead off the second. He never even reached third base. Yasmani Grandal hit a liner into the glove of Arizona shortstop Nick Ahmed. Max Muncy hit a shin-high changeup from Greinke into the ground for another out. Brian Dozier flied out to right to end the threat.

The Dodgers picked up a run off Greinke in the third. A leadoff single by Yasiel Puig set the table for Joc Pederson. He ripped a changeup into right field for an RBI single after Puig advanced to third on a bunt and a wild pitch.

The rally could have produced more. Turner followed Pederson with a single. The hit transformed Pederson into the loneliest sort of Dodger: A runner in scoring position. He was stranded at second base after Machado struck out on three pitches and Bellinger lined out.

“In the middle of the game,” Roberts said, “I thought we gave some at-bats away, to be honest.”

After Goldschmidt took him deep, Ryu settled down. He allowed singles in the third and the fourth, but otherwise prevented Arizona from advancing a runner to second base through six. He retired 10 batters in a row after Diamondbacks third baseman Eduardo Escobar singled in the fourth.

Ryu had thrown only 73 pitches. But his spot in the batting order arrived in the bottom of the seventh with the Dodgers trailing by a run. Batting for Ryu with two outs, Hernandez worked a 2-2 count. Greinke pumped a 90-mph fastball down the middle. Hernandez launched a game-tying, opposite-field solo shot. It was his 19th homer of the season, and his 12th against a right-handed pitcher.

“One of the biggest hits of the year,” Roberts said.

An inning later, Lovullo took a different approach. When second baseman Ketel Marte reached on an error, Lovullo allowed Greinke to bat. Greinke bunted Marte into scoring position, but Dylan Floro extricated himself from the jam. Lovullo was gambling that Greinke could get through the duo of Turner and Machado.

Lovullo received his answer with expedience. Greinke tried a first-pitch slider. Turner launched it into the left-field seats. The crowd leaped to its feet as Jansen loosened up in the bullpen nearby.

“When J.T. hit that homer, I was on,” Jansen said. “I felt the adrenaline hit me.”

Jansen felt ready for the assignment. After giving up two runs on Tuesday in Texas, he studied video with Honeycutt, who noted glitches in Jansen’s lower half. With his delivery out-of-sync, Jansen left too many cutters up in the zone, where they were vulnerable to opposing hitters.

Jansen avoided that fate on Friday. The tying run reached second base when Goldschmidt clipped an opposite-field double into shallow right field. Jansen recovered to strike out outfielder David Peralta with an elevated, 93-mph cutter, the pitch that has carried Jansen to three All-Star games.

He ended the night with a 94-mph cutter. The pitch hovered over the middle, but Escobar chopped it toward Machado for the third out. Jansen pointed skyward. The crowd delighted in the revival — if only for one night.

“All we’ve got to do is focus on this month,” Jansen said. “Let this month motivate me, motivate us, and for us, it’s just about going out and trying to win the division.”

andy.mccullough@latimes.com

Twitter: @McCulloughTimes