Eminem was on hand to headline Lollapalooza Brazil last night and gave the gathered masses a real treat. Normally, an Eminem show closes out with his Oscar-winning hit "Lose Yourself," but the Detroit rapper decided for this one special evening, he would instead perform the song "Fack" live for the first time.

Despite the fact that "Fack" was included on Eminem's greatest hits compilation, Curtain Call, it's widely considered to be one of the weakest tracks in his canon, which he alluded to recently on "Shady XV" where he raps, “And perform "Fack" in concert / Yo, I put that shit on a greatest hits album / Now that was awesome / It takes some massive balls to do some shit like that.” He actually teased the move a few days back on Facebook.

Working on my set list for Lollapalooza, South America...

Posted by Eminem on Saturday, March 5, 2016

Despite the song's reputation, from the video above you can tell that the audience lost its collective mind when Em busted it out to end the show. I guess the lesson here: as Jay-Z probably learned at his b-sides concert last year, is to never underestimate the rap nerd's affections for a deep cut.

FACK LIVE. Thank you Sao Paolo! #lollabr #sampa @eminem @denaunondos @alanthechemist @royceda59

A video posted by Paul Rosenberg (@rosenberg) on Mar 12, 2016 at 7:04pm PST

Eminem also performed his version of the Weeknd's "The Hills," which you can watch below.