Bryce Harper celebrates an RBI in the sixth inning. (Jonathan Newton/The Washington Post)

They grew louder and meaner and, at their peak, the Philadelphia Phillies fans issued a unified reminder of what was going on inside Nationals Park.

“We’ve got Harper!” they yelled, again and again, after Bryce Harper crushed an upper-deck, two-run home run in the top of the eighth inning. Harper used to play for the Washington Nationals, that was the subplot Tuesday night, but the result was an 8-2 Phillies win that was at least a few shades of troubling for their hosts.

This was still a nine-inning game, an important one between division foes, not just five at-bats to measure the relationship between city and departed star. And it was costly. Trea Turner, the Nationals’ 25-year-old shortstop, exited in the first after he was hit in the hand by a pitch. Matt Adams, once giving Ryan Zimmerman the day off, was taken out three innings after he fell over a railing along the first base line while tracking a foul ball.

Manager Dave Martinez later announced that Turner broke his right index finger, and there is no timetable for his return. Adams is day-to-day with back spasms. The Nationals otherwise had spotty defense, and shoddy situational hitting, and their bullpen struggled yet again. This time it was Wander Suero and Matt Grace, giving up four sixth-inning runs punctuated by an RBI single for Harper. And it was Jeremy Hellickson, a starter moonlighting in relief, allowing Harper’s 458-foot home run in the eighth.

It all triggered those sharp-edge cheers and showed, Harper or no Harper, that there are clear constants of the Nationals’ 1-3 start.

“We lost one of our good players and we lost,” Martinez said. “We got to come back tomorrow, and we got to get better.”

It was all Harper in the lead-up, for the days and hours before he was booed, mercilessly, and finished 3 for 5 with a single, double, home run and three RBI. He is at the center of the Phillies’ lineup, and the center of this rekindled rivalry, and was the center of attention for the fourth game of the Nationals’ season. Some things change. Others don’t.

The day began with a thank you message, posted to Instagram just after 10 a.m., from Harper to Washington in 286 words. Then, around 3 p.m., he sat in a full news conference room, brimming with cameras and reporters, all relaying each answer to the world. He expressed, again, his gratitude to Washington, for seven good years, for helping him grow up. He tried to explain how this felt. He teared up, his voice catching, when mentioning the baby boy he’ll soon welcome.

Then, at 7:48, after a rain-delayed start, Harper strode toward home plate for his first at-bat. The crowd booed, just as it did through a pregame video tribute, and just as it did throughout the night. It erupted six pitches later, when Max Scherzer struck out Harper with an 85-mph change-up, and they were off.

“I didn’t know what it was going to be like,” Harper said. “Heard the boos. Kind of just remembered that I have 45,000 people in the city of Philadelphia — and more — that were sitting at their TV cheering.”

But Washington fans were quickly quieted in the bottom of the inning. Turner squared to bunt, and a high-and-inside fastball from Phillies starter Zach Eflin hit his right index finger. It looked so similar to June 29, 2017, when a Pedro Strop fastball hit Turner in the right wrist. That injury, a nondisplaced fracture, sidelined him for exactly two months. This one is serious, too.

Turner yelled “Damnit!” before walking off the field, skipping down the dugout steps and going straight through the tunnel to the clubhouse. The Nationals will turn to Wilmer Difo in Turner’s absence. Turner didn’t think his hand was misplaced on the bat, leading his finger into trouble. He just wasn’t happy with Eflin’s pitch.

“I don’t expect anybody to throw basically at my head,” Turner said. “So for me, when I see the ball in that kind of tunnel, first thought is slider, maybe started up and in. I tried staying in there with the bunt, and it kept running.”

Scherzer took the second matchup with Harper, striking him out on a diving cutter in the third. Harper won the third matchup, doubling to right in the fifth, before Scherzer stranded two runners in scoring position with back-to-back strikeouts. The Nationals trailed by two runs then — the first on a Maikel Franco solo homer, the second on a passed ball by Yan Gomes — and Scherzer was done after five innings, seven hits, nine strikeouts and 96 pitches thrown.

Nationals relievers gave up 10 runs in 7⅓ innings in their season-opening series against the New York Mets. They allowed six more Tuesday, four in one crippling frame, turning Scherzer’s solid start into a lopsided loss. Suero recorded one out and put runners on the corners in the sixth. Grace then yielded a bases-clearing double to Jean Segura, and Harper plated Segura with an RBI single to make it 6-0.

Nationals third baseman Anthony Rendon lofted a two-run homer in the bottom half, giving the Nationals a hint of life. But it made just a small dent for Harper to restore. His bat whipped Hellickson’s 89-mph pitch high above the field, above the Philadelphia fans who traveled to see him, above the facing of the second level and into the first rows of seats. Harper watched it for a moment, maybe two, before flipping his bat like a pinwheel toward the Nationals’ dugout.

It punctuated his and the Nationals’ night.

“It’s the emotion of the game,” Harper said of how he celebrated the homer. “That’s it. That’s about it.”

He used to do that for Washington: perform, pump energy through the stadium from the other side. Now he doesn’t. These teams have 18 more games scheduled for this regular season, the first of Harper’s 13-year contract with the Phillies. But the Nationals need their bullpen to improve by the second one, at 1:05 p.m. Wednesday, because even the April games count.