The former Newcastle youngster and current goalkeeper took to social media after a 1-1 Tyne-Wear derby stalemate.
The Black Cats took the lead through Jermain Defoe's first-half opener.
But Sunderland were pegged back late on as Mitrovic netted with minutes to go for Newcastle, prompting delight from Kemen - who now plays in Ligue 1:
Mitroooooooooooo— pablo olivier kemen (@Kemen92) March 20, 2016
Meanwhile, current goalkeeper Rob Elliot took to social media praising Mitrovic for his equaliser and saluting the 'unbelievable' St James' Park atmosphere.
The shot stopper was pleased with Newcastle's second-half display in particular:
Great come back second half and unbelievable atmosphere especially when mitro scored. Need to take positives and keep pushing on. #nufc— Robert Elliot (@the_dilsh) March 20, 2016
Newcastle's 1-1 draw with Sunderland doesn't really help either side.
A win for Rafa Benitez's men would bring them level with the Canaries, although Alex Neil's men have hit form before the international break. Mitrovic's equaliser has certainly done Newcastle a big favour...