PHILADELPHIA -- Bryce Harper checked his swing.

Third-base umpire Angel Hernández said he swung for strike three.

Harper got angry, got ejected, stormed Hernández, then tossed his helmet into the stands behind the Phillies’ dugout in the third inning of Thursday night’s 3-2 loss to the Pirates at Citizens Bank Park. The helmet bounced off somebody’s hands and landed in the aisle between two sections. Chaos ensued.

“A bunch of dads went after it,” 10-year-old Hayden Dorfman said. “My dad had a pretty good grip on it, it looked like. I tried going in, but then a lot of people started saying, ‘Give it to the kid.’ Then I got it.”

Dorfman came to the game on Thursday in his powder blue Bryce Harper jersey, hoping to get the Philadelphia slugger to sign it. Instead, he got Harper’s helmet, which Harper later signed. Dorfman, who is a fifth grader at Kresson Elementary School in Voorhees, N.J., proudly wore his newest, most-prized possession throughout the night.

He could not stop smiling.

Harper was happy to make the kid’s day, but he lamented the fact that he got ejected in the first place.

“I never want to get thrown out of a game,” he said. “I never want to be on that side of it and make somebody’s night in that situation, because this was our last game at home in the regular season. Not many of these people are going to be able to afford tickets to a postseason game. It’s a very tough ticket to get, especially with what we have right here. Getting thrown out of a game like that, it’s not fun. They might see me for the last time this year. I don’t like that.”

Harper said he hadn’t seen a replay of his check swing. He said he didn’t need to.

“It’s just bad, just all around,” Harper said. “You’re grinding in that at-bat, facing a guy I’ve never faced before. I got to a 3-2 count, I took a slider down and in, obviously didn’t go. Wasn’t even thinking about [strike three] in that situation. I was taking my stuff off and I heard the crowd’s reaction, and I was just like, ‘There’s no way.’”

Asked what Hernández told him when he went out to third base, Harper said, “He just told me that if I saw the replay, that I would know that I was wrong. I mean, yeah, so.”

Harper said he got everything out of his system when he decided to toss his helmet into the stands.

“I didn’t need it anymore,” he said.

Once Harper got to the clubhouse, he sent a couple people into the stands to see if Dorfman wanted the helmet signed. Of course, the kid said yes. 

“He was super happy,” Harper said.

Dorfman can thank his father, Aaron, for getting the souvenir in the first place. Aaron got a grip on the helmet as it bounced in the aisle and immediately assessed an escalating situation.

“I picked up the helmet, then four other grown men came for it,” Aaron said. “It was very clear that I was not going to be winning any pulling matches with the helmet. At which point I saw [Hayden] standing next to me, and I decided the most effective way of possibly getting the helmet was saying, ‘Give it to the kid.’ Then other people started saying, ‘Give it to the kid.’ And this adorable young man was standing there. Then it became less of a muscle match.”

Genius.

“I’m probably going to put it in my room,” Hayden said.

The Dorfmans have a partial season ticket plan, so they attend quite a few games. Hayden has been coming to games since he was a baby, so he knows this doesn’t happen every day. Or even every season.

In fact, it only seems to happen once every 20 years.

The last Phillies player to chuck equipment into the stands during a game? It might be Kevin Millwood, who tossed his glove into the crowd on Sept. 28, 2003 -- exactly 20 years ago to the day -- after being pulled in the fifth inning and getting booed during the final game in Veterans Stadium history.

Hayden said he doesn’t know what the reaction will be at school on Friday. He thought about bringing the helmet to school. He might not.

“All my friends are Phillies fans,” Hayden said. “I told them to watch on TV to keep an eye out for me.”

No way could they have missed him.