They came, they saw and they rocked SoCal fans with one of the biggest hard rock and metal events of the year. Headliners Slipknot and Judas Priest were joined over three days by a powerful collective of acts, leaving thousands of fans rocked.

The Saturday bill was headlined by metal icons Judas Priest, who delivered a blistering set with an impressive light show, mixing in Redeemer of Souls favorites like the show opening "Dragonaut" and "Halls of Valhalla" with classics like "Turbo Lover," "Breaking the Law," "Hell Bent for Leather," "You've Got Another Thing Comin'" and the encore "Painkiller."

While Korn have been revisiting their self-titled debut on tour, their Knotfest set found the band playing the album's first seven songs to the delight of the crowd until "Shoots and Ladders" gave way to "Somebody Someone" with a sea of arms from the audience waving along. Korn favorites from other eras included "Here to Stay," "Did My Time," "Coming Undone" and the set-closing "Freak on a Leash."

Mastodon, Trivium and Corrosion of Conformity also enjoyed sets on the Main Stage during Saturday. Mastodon's psychedelic-looking set featured he band playing fan favorites like "The Motherload," "High Road," "Black Tongue" and the show closing "Blood and Thunder," while Trivium rocked the house with the "Silence in the Snow" title track and "Until the World Goes Cold" off their new album, weaving it in with "In Waves" and "Dying in Your Arms" among others. As for Corrosion of Conformity, fans were energized by the fact that Pepper Keenan was back with the band. The group's set opened with "My Grain," ended with "Clean My Wounds" and included such standouts as "Seven Days," "Paranoid Opioid" and "Albatross."

Prior to the Main Stage festivities, there were three stages in the fields by the San Manuel Amphitheater providing lots of rock and metal for fans to check out. Early day highlights included the traditionally messy and rocking spectacle that is GWAR, a thrashy, swagger-filled set from "Ice 'Motherf---kin' T B-tch" (claiming he changed his name) and his band Body Count, well received sets from At the Gates and Goatwhore and early day rocking from Red Fang and Battlecross. It appeared as though Body Count received the biggest crowd response on the side stages, with fans getting into "There Goes the Neighborhood," "Talk S--t, Get Shot" and the show closing "Cop Killer." Ice-T, the ultimate showman, also entertained the crowd with some jokes during a break for a technical issue. Meanwhile, Kataklysm, Belphegor, Khaotika, Chasing the Bullet, Kaustik and Hemlock all delivered solid sets on opening day as well.

As for the Sunday lineup at Knotfest, weekend hosts Slipknot made their presence felt. After "XIX" played over the loud speakers, the band opened with "Sarcastrophe" amidst the stunning visuals that fans have come to expect. Chris Fehn, Shawn Crahan and Sid Wilson all found themselves on platforms that could maneuver up and down onstage, while a spectacular pyro and light show accompanied the heavy hitting sounds. On top of standouts like "The Heretic Anthem," "Psychosocial," "Wait and Bleed" and "Before I Forget," the band dug into the catalog for the occasion, pulling out the rarity "Me Inside" for the performance. Finishing out the night on a high note, the band's encore include "(sic)," "People = S--t" and "Surfacing."

Bring Me the Horizon, playing nearly silhouetted against a light wall early on, warmed the crowd, opening with "Happy Song" and "Got to Hell (For Heaven's Sake)." As their performance went on, the crowd got a little more into it with the BMTH standouts "Shadow Moses," "Throne," "Sleepwalking" and the set closing "Drown."

Clutch delivered one of the highlights of the night with their high energy set led by Neil Fallon's demonstrative stage moves. Opening with their current single "X-Ray Visions" and including other new album favorites like "Sucker for the Witch," "Noble Savage" and "Decapitation Blues" mixed with such older favorites as "Crucial Velocity," "The Elephant Riders," "DC Sound Attack" and "The Mob Goes Wild." Opening the Main Stage with a change of pace was Mobb Deep playing with Ghostface Killah.

Sunday's side stages provided plenty of rock and metal as well. It might have been a tie as to which act was greeted most warmly by the crowd, with both Suicidal Tendencies and Snot receiving plenty of love from the SoCal fans. Snot's performance in particular raised the energy level and delivered some of the most reverberating beats of the day. Cannibal Corpse had the hair twirl and guttural vocals going on full volume. Meanwhile, Beartooth, Kyng and Devour the Day also turned in solid sets. Early day highlights on some of the other stages included a blistering set from The ReAktion, the heavy brutality of Dying Fetus and day opening sets from Darkest Day and Kings of Carnage.

Knotfest also included plenty of other attractions as well. Street Drum Corps played at the top of the lawn. There were motorcycle and monster truck exhibitions, opportunities to meet the bands, a full-on runway of vendor booths and plenty more to take in. All in all, Slipknot have made Knotfest a "must attend" event if you're a heavy music fan.

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