Anna Kendrick [1] gave Jennifer Lopez [2]'s famous derriere a run for her money in last night's episode of Lip Sync Battle, with John Krasinski [3]. Anna rocked a choreographed dance routine while performing "Booty," Jennifer's hit song with Iggy Azalea [4]. Anna owned the stage, especially when she rapped Pitbull's part of the song, but when Jennifer walked out in a surprise appearance, both John and color commentator Chrissy Teigen [5] lost their minds. Meanwhile, John pulled out all the stops when he shimmied in a bright sequined dress while performing Tina Turner's hit "Proud Mary." Check out the pair's funny battle above, and then look at Anna and John channeling their favorite boy bands [6] and Anne Hathaway's untouchable "Wrecking Ball" performance [7] from last week's episode.