There are certain dates -- Oct. 21, 1980, and Oct. 29, 2008, leap to mind -- that live in the annals of Phillies history. And depending on how the next, oh, 13 years or so play out, this could end up as one of those moments.

Where were you, people might ask, at 6:45 p.m. on March 30, 2019?

Rhys Hoskins will recall it exactly: On-deck circle, Citizens Bank Park. “Front-row seat,” he said.

Nick Williams was in the Phillies’ dugout, having never before seen a ball hit so far with one of his bats.

A Braves fan from Tennessee was seated in Section 201, the second deck in right-center field, some 465 feet from home plate, where the ball finally landed.

And then there were the 44,597 strong, a second consecutive sellout crowd, that came to South Philly for the second game of the Bryce Harper era -- an 8-6 victory over the Braves -- and witnessed history instead.

Where were you when Harper got his first hit -- a home run, of course -- with the Phillies?

“I just kind of had my mouth open,” Hoskins said. “Jaw dropped. It was kind of, wow. I don’t think you could write it any better.”

OK, let’s try.

For the sake of posterity, Harper’s homer -- a solo shot in the seventh inning against Braves reliever Jesse Biddle, a Germantown Friends product and former Phillies first-round pick -- left the bat at 113.7 mph, according to Statcast. It was the second-longest homer of Harper’s career, trailing a 473-footer last May 4 against now-Phillies teammate Nick Pivetta. It gave the Phillies a 7-4 lead and wound up as the winning run.

And even for Harper, a former No. 1 overall pick who has hit 185 regular-season home runs and five in the playoffs since breaking into the majors at age 19 in 2012, there was something special about this one.

That’s probably why, when the fans beckoned him for a curtain call, Harper emerged from the dugout, pumped both fists, and screamed, “Let’s go!” as loud as he could in a visceral scene reminiscent of when he won the home-run derby last July in Washington as a member of the Nationals.

“It was really cool, definitely one of the cooler homers I’ve ever hit,” said Harper, greeted by “M-V-P!” chants when he returned to right field in the eighth inning. “Just the fan base, just the stadium, the electricity we had in this place, it all came together.”

There were other big swings along the way to the Phillies’ first 2-0 start since 2011.

Maikel Franco went deep for the second time in as many games to open a 4-3 lead in the fourth inning; J.T. Realmuto, whose arrival in a February trade with the Marlins was as big a move for the Phillies as signing Harper to a 13-year, $330 million contract three weeks later, broke a 4-4 tie with a two-run homer in the fifth.

And big swings are quickly becoming the Phillies’ signature. They hit six home runs in the first two games. No team in franchise history had ever hit more than five.

“I think that’s going to be the defining characteristic of our team,” manager Gabe Kapler said. “An offensive club that’s relentless and gets big hits, scores a lot of runs, is patient, and wears opposing pitchers down.”

But there’s just something about Harper. He stands out in a crowd, for reasons that go beyond the neon green Phanatic cleats that he wore on opening day. Eyes can’t help being drawn to him. His at-bats are more than at-bats. They are events.

Harper was 0-for-3 with a walk on opening day and 0-for-2 with a walk when he came to the plate in the seventh inning. He never had any success against Biddle, either -- 0-for-5 with four strikeouts.

But Harper knows Biddle. Pretty well, it turns out. He was Biddle’s catcher on a USA Baseball amateur team when they were teenagers. They were drafted 26 spots apart in 2010, and they played against each other in the minor leagues when Biddle was in Lakewood, N.J., and Harper in Hagerstown, Md.

“He’s actually dominated me,” Harper said. “I felt like every time I faced him he has something against me. I was able to get the job done today against him. He’s a great pitcher, great guy. Got him.”

Harper was borrowing a bat from Williams, the outfielder whose spot in right field he now occupies. Biddle threw him three consecutive fastballs. Harper took the first one for a ball and the second for a strike before connecting.

And just like that, everything else melted away. A rough debut for Nick Pivetta, the right-hander upon whom the Phillies are counting for so much this season. Three early-inning baserunning mistakes that Kapler said the Phillies must address. A ninth-inning tightrope walk by veteran reliever David Robertson. All topics for another day.

The Braves fans from Tennessee agreed to give Harper the baseball as a keepsake in exchange for some signed memorabilia. And Phillies fans everywhere won’t forget where they were when it happened.

“That’s the loudest I’ve ever heard it here,” Hoskins said. “And I think there’s more in there. We’re in March. What happens when we’re in September and October?”

There’s always room for more memories.