Jay Z fans have been left in a spin following the rapper’s surprise appearance at Justin Timberlake’s Brooklyn concert over the weekend.

Hopping onstage to perform their 2013 collaboration Holy Grail, the lead single from Jay Z’s previous studio album Magna Carter Holy Grail, the musician’s appearance sent the Barclays Center crowd wild.

Catch the full performance below; Justin Timberlake’s set at the Brooklyn concert was one of the last in his sold-out global tour, in support of last year’s double-album The 20/20 Experience.