Kendrick Lamar and Imagine Dragons epic GRAMMY Awards mash-up performance.

The best performance of last night’s Grammy Awards may have been Kendrick Lamar and Imagine Dragons mashup of Record Of The Year-nominated single, “Radioactive,” and  “m.A.A.d city,” off Kendrick’s Album Of The Year-nominated album, good kid, m.A.A.d city.  Watch the video above.