For three days last week at Citizens Bank Park, the Phillies proved to the rest of the world what they claimed everyone within their clubhouse already knew. They can go toe-to-toe with the mighty Braves and stay on their feet.

But winning in Atlanta? They haven’t mastered that yet.

When the Phillies travel to Georgia, strange things happen to them. Ace pitchers are unable to command their fastball. The young third baseman reverts to playing the quality of defense that once made some rival scouts wonder if he would need to change positions. Managers lose track of how to make a pitching change.

Each of those things -- plus a two-run home run by Braves superstar Ronald Acuña, a three-run shot by pinch-hitting Ehire Adrianza, and a three-run blast by Freddie Freeman -- conspired against the Phillies in an 8-1 thumping Friday night in the opener of a three-game series.

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And because, at last check, the road to the National League East title still runs through the three-time defending champion Braves, the Phillies will have to figure out how to play better at Truist Park. They are 7-16 in 23 games there since the beginning of the 2018 season, 12-20 overall since the 5-year-old ballpark in suburban Atlanta opened.

Acuña took over the game in the middle innings. After the Phillies held him to 2-for-12 with five strikeouts in their three-game sweep last week, Acuña doubled in the third inning, gave the Braves a 2-1 lead with a titanic homer in the fifth, and made a leaping catch in right field in the sixth that likely prevented the Phillies from tying the game.

“He’s a great player,” Phillies manager Joe Girardi said. “When he centers a ball, it’s loud. I mean, it’s really loud. We weren’t able to keep him from centering balls tonight, and that was the big difference in the game. We did a really good job with him at our place. We weren’t able to do that tonight.”

Zack Wheeler flirted with danger but escaped scot-free in the first four innings before the Braves finally got to him in the fifth. Atlanta broke it open in the sixth against reliever Brandon Kintzler.

In between, Girardi had to remove Wheeler from the game when he came to the mound in the middle of an at-bat with two out in the fifth inning after forgetting that pitching coach Caleb Cotham had made a mound visit earlier in the inning.

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It’s likely Wheeler, at 94 pitches, was facing his last batter anyway. And Kintzler was ready to come into the game, unlike when former manager Gabe Kapler summoned Hoby Milner into the first game of the 2018 season -- also in Atlanta -- before Milner had properly warmed up.

Still, it was an uncharacteristic goof for Girardi, who started walking back to the dugout when home-plate umpire Carlos Torres informed him that it was the Phillies’ second visit.

“I screwed up,” Girardi said. “I was worried about his pitch count and how hard he worked, and I screwed up.”

Said Wheeler: “Honestly, I was so into the zone and into the game right there, I didn’t recognize it either. We said what we said out there, we broke, and I didn’t even think twice about it. Those kind of mistakes happen. It’s human.”

Wheeler may have still be thinking about the pitch to Acuña. He tried to throw a slider on the corner of the plate. Instead, it “just spun right down the middle,” Wheeler said, “and he did what he did.”

Acuña stood at the plate and admired his shot, which traveled 456 feet, according to Statcast.

Was Wheeler bothered by Acuña’s reaction?

“Whatever,” he said.

Ozzie Albies followed Acuña with a double. But three batters later, Wheeler was one pitch from capping the deficit at one run when Travis d’Arnaud hit a two-strike slider for an RBI single to left field. Kintzler inherited a 2-0 count from Wheeler and struck out Dansby Swanson to keep it at 3-1.

Alec Bohm made a bid to tie the game in the sixth. With two on and two out, he lined a ball that looked like it might go over Acuña’s head. But Acuña made a leaping catch in deep right field.

“You talk about on the offensive side; he did it on the defensive side,” Girardi said. “It’s a center fielder playing right field is what it is. We’re going to score two there. It’s going to be 3-3 in that instance if that ball gets over his head. He made a great play there, too.”

Bohm made two errors at third base to open the bottom of the sixth. His low throw to first enabled Austin Riley to reach base, and he couldn’t knock down Cristian Pache’s bouncer to third. That set the stage for Adrianza to hit a three-run homer that all but put the game out of reach before Freeman went deep in the eighth.