JAY Z is currently in the middle of a multi-date stop at London's O2 Arena, and he came prepared.

The Roc Nation chief brought out Coldplay's Chris Martin on Friday night for a rendition of the former's "Heart Of The City (Ain't No Love)," off Hov's 2001 album, The Blueprint, which samples soul singer Bobby Bland's own 1974 tune "Ain't No Love in the Heart of the City."

JAY Z has two more dates at the O2, including one on Saturday night.

Watch a clip of the performance below via fan footage.