Topping the sheer magnitude of Paul McCartney’s Lollapalooza headlining slot on Friday may have been impossible, but following up with one of the most enduring hard rock acts of the last 30 years and a red hot pop/R&B crooner from today ran a fairly sizeable second. No, Metallica might not have a shred of musical communality with Sam Smith, but it provided a perfect split for fans of each act to go their separate ways without feeling remorse for missing out on either.

Considering Smith’s shortcoming, this particular critic wasn’t enticed to “Stay With Me” any longer, so it was back to Metallica for a thunderous, adrenaline-infused finale.

And for the small sliver of concertgoers stuck somewhere in the middle of both worlds, the ideal place to begin was Metallica, if only for its slightly earlier start time and the ability to obtain a litmus test of members’ current tenacity. But all it took was James Hetfield’s single shout of “Gimme fuel, gimme fire, gimme that which I desire” and the veterans were off to races, which alongside fellow scorchers “For Whom The Bell Tolls” and “Wherever I May Roam,” indicated time has only enhanced the band’s balls to the wall aggression.

As the metal mavens were kicking into high gear, this year’s Grammy darling Sam Smith was cuing up selections from his multi-platinum debut “In The Lonely Hour” across Grant Park with a fleet of slick musicians and soulful background singers. Although his tender balladry probably wouldn’t do much for those on the opposite end, there was no ignoring the stunning, almost heavenly quality of his pipes that never really wavered (outside of a nervous tickle or two).

However, even with talent oozing out of every vocal chord, Smith was a somewhat reserved performer who probably wouldn’t have any problem selling a plethora of soft-spoken and periodically beat-driven pop in a theatre, but he couldn’t quite captivate those conversing on the outskirts of the massive crowd. Considering the shortcoming, this particular critic wasn’t enticed to “Stay With Me” any longer, so it was back to Metallica for a thunderous, adrenaline-infused finale.

Though the guys pushed past the slated curfew to address remaining “Black Album” classics, it was more than worth the slightly later night, especially as the crowd roared over “Nothing Else Matters” and fist pumped to the pummeling beats of “Enter Sandman.” Even without anything new to offer, the group breathed thrilling life into a consistently brawny back catalogue, and by the end of the retrospective, it was clear Metallica has little competition past or present when it comes to ruling the heavy ranks.