Dodgers bullpen blows it as Gerardo Parra hits grand slam to lift Nationals

Gerardo Parra was wearing a different uniform with a weird number at Dodger Stadium on Saturday. He wasn’t No. 8 for the Arizona Diamondbacks, Colorado Rockies or San Francisco Giants, a trio of division rivals, anymore. He was No. 88 in red and navy, signed to the reeling Washington Nationals on Thursday to supplement a weakened roster. The switch did not change his treatment of the Dodgers.

Designated for assignment by the Giants last week, Parra continued tormenting Los Angeles in his second game as a National, smashing a go-ahead, two-out grand slam off Dylan Floro in the eighth inning of the Dodgers’ 5-2 loss. Parra’s first hit as a National was, fittingly, his eighth career home run against the Dodgers. It’s the veteran outfielder’s most against any club over his 11-year career.

The swat deflated an amped crowd begging for Floro to escape the predicament he was assigned to defuse. The right-hander, carrying a 0.00 earned-run average in 17⅓ innings, was summoned with the bases loaded and one out in an inning that had gone wrong after seven shutout frames by Walker Buehler.

Dodgers third baseman Justin Turner had put the tying run on base, fielding a potential double-play ball and throwing it into right field, leaving runners at first and third with no outs.

“I went back and looked at it,” said Turner, who provided the Dodgers’ runs with a homer off Max Scherzer in the third inning. “My feet were under me, I was under control. It just sailed a little bit.”

Juan Soto, the Nationals’ wunderkind playing his first game since coming off the injured list, smacked a line-drive single off Scott Alexander on the ninth pitch of the at-bat after fouling off six straight pitches. The hit sliced the Dodgers’ lead to one.

Floro entered to face the dangerous Anthony Rendon. He got the right-handed slugger to strike out on the eighth pitch of the clash, a 94-mph sinker. He got to two strikes on Parra too, but left a center-cut fastball Parra didn’t miss. Suddenly, the Nationals led after not scoring over the previous 16 innings.

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“And as we know with Parra, he likes the fastball,” Dodgers manager Dave Roberts said. “And when you make a mistake he’s going to make you pay. Unfortunately, that’s what happened.”

Just like that, Buehler’s effort in outdueling Scherzer was wasted. The young right-hander, facing a three-time Cy Young winner, was almost untouchable after an odd first inning.

Nationals leadoff man Adam Eaton sparked the strangeness with an excuse-me, check-swing single to left. Victor Robles followed with a push bunt to second baseman Enrique Hernandez, who attempted to tag Eaton as he sprinted by but couldn’t reach and spun to make an off-balance throw to first. The ball bounced away from first baseman Max Muncy, Eaton advanced to third and Robles went to second on the error.

Soto drew a walk to load the bases — for a split second. Then the Dodgers’ fortunes suddenly reversed. Inexplicably, Robles jogged halfway between second and third after ball four — perhaps thinking the bases already were loaded and the walk was pushing him to third. He realized his head-scratching gaffe too late. Dodgers catcher Austin Barnes fired a throw to second in time to pick off Robles and steal an out.

Buehler did the rest, getting Rendon to fly out and striking out Parra on a curveball in the dirt to wiggle free.

After that, Buehler breezed, giving up two more hits and no more walks over seven innings. He retired 18 of his last 19 batters and the final 12. He struck out seven. He threw 97 pitches, incorporating the mechanical adjustments he’s implemented as he’s gradually improved with each start.

“Here and there you find something, a different feel, a different mechanic, or something you’re not quite doing like last year,” Buehler said. “And I think the past few outings, I think I’ve gotten a little bit closer, and we’ll keep trying.”

On the other side, bad luck, shabby defense and little run support have plagued Scherzer this season, and had left the Nationals 1-7 in his first eight starts.

His only trouble Saturday, however, was self induced. Scherzer retired the first two hitters in the third inning before Muncy fell behind 0-2 and fought back to work a walk. Turner capitalized on Muncy’s labor and crushed a fastball over the fence in center. It was Turner’s fifth home run in four games and sixth this season after not homering in his first 122 plate appearances.

The tumult did not derail Scherzer. He powered through seven innings, pushing his pitch count to 115 — a total rarely reached in today’s age of coddled arms. He departed with the Dodgers holding a two-run lead that seemed so much bigger until it vanished with one swing from a familiar nemesis.

jorge.castillo@latimes.com

Twitter: @jorgecastillo