Eminem unleashed his new album "Recovery" on Monday (June 21), but the Detroit rap star gave a lucky few hip-hop heads at New York's Bowery Ballroom an extra treat later that night, performing a quick set at a freestyle rap battle event dubbed Red Bull EmSee: The Road to 8 Mile.

Eminem's "Recovery" album leaked two weeks before it's release date, so the Detroit rapper decided to push the release up -- by one day. "Recovery" is Em's second album in about a year ("Relapse" was released on May 19, 2009) and finds the now sober MC depicting his life experiences post-dependency.

At the New York City nightclub, after a series of MC battles and a performance by underground all-star group Slaughterhouse, Eminem charged the stage with "Despicable Freestyle," rhyming to the beats from Drake's "Over" and Lloyd Banks' "Beamer, Benz or Bentley," supplied by DJ Alchemist. He then performed two new songs off "Recovery" -- the blistering "On Fire," and the Pink-assisted "Won't Back Down" -- before saying a quick goodbye.

"I do realize man, for real, that if it were not for you guys I would not be standing up here right f***** now," Em told the crowd. "Honest to God, man -- thank you to each and every one of you." As he left the stage, fans kept chanting for an encore that never came.

Earlier on Monday, Eminem traded verses with Jay-Z on the rooftop of the Ed Sullivan Theatre for another intimate performance that will air on CBS' "Late Show with David Letterman" this Friday (June 25). Jay-Z had originally planned to perform on the building's famous marquee, but he reportedly switched locations after Drake's free concert in South Street Seaport turned into a near riot last week.

Eminem and Jay-Z will reunite for two hometown stadium shows this September. The Detroit MC will headline Comerica Park Sept. 3, while Jay-Z will front a concert at New York's Yankee Stadium on Sept. 13.

Though "Recovery" hit the Internet a full two weeks before its release date, Eminem recently told Billboard.com he's not stressing the leak. "Nowadays, you can't control it," the rapper said. "We could go back and forth all day about the pros and cons of the Internet and that whole thing, but why fight it? You can't do anything about it, and as long as the response is good to the record and people enjoy it, then it is what it is."