A first-half blitz saw 'Los Cules' go into the half-time interval 3-0 up thanks to a brace from Luis Suarez and a goal from talisman Lionel Messi.
However, it wasn't long after the break that Barcelona extended their lead even further.
Iniesta exchanged passes with Messi before completely selling opposing goalkeeper David Soria with a beautiful dummy to give him an open goal.
It was the narrowest of angles but the Spanish midfielder made it look easy in what could be his last final in a Barcelona shirt.
Check out the goal for yourself:
April 21, 2018