Run-DMC perform during day 2 of Budweiser Made in America festival on September 2, 2012 in Philadelphia, PA
Shannon Stewart for Fuse

By early evening of the second and final day of Made in America, Jay-Z’s massive festival on the Benjamin Franklin Parkway in Philadelphia had already delivered its share of big names and dynamic sets: Skrillex, Rick Ross, Passion Pit, Jill Scott, the return of D’Angelo, and of course Jigga’s own sensational headlining performance on Saturday night.

But at 5:45 p.m. sharp on Sunday, things took a turn toward the poignant—with plenty of old-school thrills attached—when pioneering hip-hop legends Run-D.M.C. tore onto the main stage beneath a huge “Jam Master Jay Forever” video banner. They immediately had thousands of arms in the air, wavin’ like they just don’t care, with the one-two punch of “Rock Box” and “Sucker M.C.’s,” both from the group’s groundbreaking, self-titled 1984 debut LP.

Photos: See more shots from the dynamic Run-D.M.C reunion

“Damn, this feels good,” gushed Joseph “Rev. Run” Simmons, decked out in a black Adidas track suit, as he looked out at the cheering crowd and then smiled over at Darryl “D.M.C.” McDaniels, who was sporting a black Alice in Chains T-shirt. The 45-minute, 12-song set marked Run-D.M.C.’s first show in over a decade—a reunion few thought would ever happen following the 2002 shooting death of Jason “Jam Master Jay” Mizell at his Queens, New York recording studio.

Jay’s spirit loomed large over the proceedings, whether it was his iconic beats fueling rousing versions of “It’s Like That” and “It’s Tricky,” or the posse at the side and rear of the stage decked out in black Stetson hats and thick gold rope chains in tribute. Backed by two DJs (who weren’t introduced to the crowd), Rev. Run and McDaniels—whose chemistry and mic skills were still well intact despite the long layoff—honored their late partner-in-rhyme by doing justice to a litany of hits: “King of Rock,” “Mary, Mary,” “Run’s House,” and an especially fiery “Down With the King” included.

Midway through the set there was a commotion as Jay-Z and Beyonce, walking hand-in-hand—flanked by beefy security guards and chased by hundreds of rabid fans with cell phones in the air trying to Instagram the scene—made their way through the crowd and got up front to take in the historic moment.

“You know what to do when I do it,” said Run, crouched low and close to McDaniels at the lip of the stage. “Do it!” McDaniels returned, before the pair launched into the tongue-twisting rapid-fire intro to “Peter Piper.”

Then came the emotional juncture everyone had anticipated. “Some years back, my DJ got assassinated, and at that point we said, let’s break the group up,” said Run, as McDaniels bowed his head. “Without Jay, you know, let’s just call it a day ’cause Jam Master Jay was everything to us. So we put a silence on the group.”

But the duo had one last way to honor their fallen comrade during their triumphant return, welcoming his two sons—Jason “Jam Master J’son” Mizell, Jr. and T.J. “Dasmatic” Mizell—to the stage, each taking solo turns on the decks to show off their own impressive turntable skills.

“I know you’re lookin’ from heaven, Jay,” said Run. “I brought your kids out here, man.”

Jay’s progeny stuck around to help close out the set with “My Adidas” and “Walk This Way.” Taking in the roaring crowd one final time, the clearly moved Rev. Run pointed at Jay-Z, repeatedly mouthing “Thank you, thank you.” As Run and McDaniels made their way off the stage, Beyonce rushed over and hugged the pair—an exclamation point on a huge Run-D.M.C. embrace in Philly that won’t soon be forgotten.