Bruno Mars will start 2011 as America's pop chart king - his GRENADE has blasted Katy Perry's FIREWORK off the top of the Billboard Hot 100.
Perry falls to two as both top tracks make history as digital downloads, scoring two of the biggest sales weeks ever.
Only Flo Rida and Ke$ha have had better weeks online.
Talking of Ke$ha, her We R Who We R ends 2010 by jumping back up the chart to three, while What's My Name? by Rihanna and Pink's Raise Your Glass round out the new top five.