My prediction: Barcelona 4 - 1 Milan Barca to score first, quickly followed by a Milan equaliser which will make it 1-1. Barcelona will then get a penalty which Messi will convert to make it 2-1. In the second half Barcelona will make the 3-1 (Milan would still go through with this result). So somewhere in the last 5 minutes Barcelona will get a 2nd and most likely very disputable penalty. If the penalty is converted Barcelona will go through, if not then Milan will. But I hope for a 0-3 Milan victory