Denmark had scored a lighting-fast goal through Mathias Jorgensen to take the lead in the match in less than a minute.
However, the lead was not to last long. Just three minutes later the Juventus striker managed to strike back.
Following a cross in to the box from the Croatians the ball was seemingly cleared away from goal.
However, the ball hit Andreas Christensen in the face and rebounded in to the path of the opposition forward.
Mandzukic hit the ball first time in to the ground, with the ball going past a dumb-founded Kasper Schmeichel in the Danish net.