The championship game of the Rumph Classic — Philadelphia’s premier summer pro-am basketball tournament — was already set in 2016 when Mike Morak received a text message from Marcus Morris hours before tip-off.

That player who was listed on the roster of Team F.O.E. — the squad led by Marcus and his twin brother, Markieff — but had yet to suit up? He was in town, set to play that night. James Harden, Marcus Morris texted Morak, was “Rumph ready.”

Harden soon tweeted the news — one of the NBA’s biggest stars would be playing at La Salle University in support of the Rumph foundation — and lit up Philadelphia’s Twittersphere, similar to the way his trade to the Sixers did on Thursday.

“The whole city just exploded,” said Morak, the tournament’s director. “My phone exploded.”

Harden had already played in the NBA Finals and made four All-Star teams before he arrived at Tom Gola Arena that night. Still, he had to check in at the registration table in the lobby and pick up his uniform like the rest of the players.

Joel Embiid and Allen Iverson watched from the baseline as Harden — who ripped the Nike logo from his black Rumph Classic jersey (he had recently signed with Adidas) — chirped with fans in the front row, knocked down a three from way behind the arc, and turned back to see if the fans still had something to say.

The renowned shooter celebrated buckets with his signature stir of the pot and tossed alley-oops to the Morris twins. Harden went one-on-one for a series of possessions with former Simon Gratz star Malik Alvin, and famed North Philly streetballer Aaron “A.O.” Owens heckled him from the crowd. Harden flexed his muscles after driving the lane en route to helping Team F.O.E. win the title.

“In an environment that some players shy away from, JH stepped right into and embraced and won the crowd over,” Morak said. “He walked in as a normal guy shaking everybody’s hand and wanting to feel what was really going on. He’s not like, ‘Oh, I’m going to wait here until the game starts.’ He was like, ‘Cool. We’re out there?’ Walked across the court, sat down, talked to the kids, and took a bunch of photos. I can’t say enough how much I know this city will embrace him because he’s just a great guy who loves to play basketball.”

The fans who rushed to Olney after seeing Harden’s tweet and lined up outside Tom Gola Arena got what they wanted. It was just one game, but Harden — six years before officially joining the Sixers — brought the full experience to Philadelphia when he crashed the Rumph championship game.

“It was incredible to get the note that he was on the way and incredible that he showed up,” Morak said. “He was a great guy and I ran into him at an All-Star Game event and we briefly spoke about it. He was like, ‘I’m a hooper. I love to play and I love the environment.’ He always showed love to the city for the experience of playing in the Rumph.”

The Rumph Classic started in 2006 as a way to honor Danny Rumph, who died on Mother’s Day in 2005 while playing basketball at the Mallery Rec Center in Germantown. The cause of death was hypertrophic cardiomyopathy, a heart disorder associated with sudden cardiac arrest. The same condition also killed Murrell Dobbins Tech great Hank Gathers in 1990 while playing for Loyola Marymount.

Rumph was home on break from Western Kentucky, where he was the team’s point guard after starring at Parkway High School.

The tournament raises money for the Daniel Rumph Foundation, which raises awareness for sudden cardiac arrest, provides heart screenings for young athletes, donates defibrillators to community rec centers across Pennsylvania, and hosts youth basketball teams.

“Danny was just an amazing guy and a fun-loving dude who everyone liked,” Morak said. “I think that added to us getting together and everyone wanting to remember him.”

Morak and Rumph were part of a tight-knit group neighborhood kids who played in after-school leagues at Mallery and returned there for pickup games as their basketball journeys continued in high school and college. That crew is the foundation for the Rumph Classic, which started at Mallery — which is now the Rumph-Mallery Recreation Center — before outgrowing the rec center and moving to college gyms.

Nearly every notable Philly high school and college hooper of the last 20 years — from Rasual Butler, Hakim Warrick and Dionte Christmas to Amile Jefferson and Scoop Jardine to Quade Green and Dion Waiters — has taken part.

Morak, a sports marketer who spent years working in basketball, would often hear about how the Morris twins and other Philly players would talk in NBA locker rooms about the Rumph Classic. If a player wanted a good run in the summer, they told them to give Philly a shot.

That word eventually reached Harden, who had played with Marcus Morris on the Houston Rockets.

“I can tell you that Marcus and Markieff don’t get enough credit in terms of how much they love Philadelphia and how much they talk about their own experiences here to other people,” Morak said. “The twins are looked at as enforcers in the NBA, but at the end of the day they’re two great people who do a lot for Philly.”

After his team won the semis, Marcus Morris told Morak before the championship that Harden — whom the twins had put on their roster with the hope that he would eventually show — was flying to Philly for the game. Morak told Morris to alert him when Harden landed in Philly, understanding that a lot can change before one of the NBA’s premier players actually gets to Olney. The following afternoon, Harden was ready.

Morak’s phone was soon buzzing and the gym was filled that night. The opposing team — which included South Jersey’s Jason Thompson and Kyle Hines — now had to prepare for a new challenge. James Harden was crashing the championship game. And even the other team didn’t mind.

“That’s the epitome of what Philadelphia is as a whole,” Morak said. “The crowd, the players, and the atmosphere was a great representation of Philly. Those guys looked forward to playing against him. Those guys wanted every bit of that competition. The fans were going at James Harden just as much as the players because they wanted to see something special and he didn’t back down one bit.”

“At the end of the day, it’s all in the fun of the sport.”