Big Sean performed live on Friday night at Power 99's Powerhouse concert in Philadelphia, and to surprise the Wells Fargo Center crowd, he brought out French Montana to rock their collabo "Mula," off his latest mixtape Detroit, for the first time ever. Watch above, and stay tuned for French's new mixtape Mac & Cheese 3 coming November 9, and Big Sean's sophomore album Hall Of Fame, which features his latest single "Guap," dropping December 18.

[via XclusivesZone