Wawrinka S. vs Cilic M. prediction

Marin Cilic had a very easy match in quarter-finals because Anderson retired after what he lost first set with 6-3 and had no chance in the second one. Stan Wawrinka won with 3-0 against Monfils and you could said that he had an easy match but it wasn't. Monfils had the support of the fans and he fought for every single point. I know that Wawrinka is more tired than Cilic but he is still a better player than him. Cilic lost most of the matches against Wawrinka and although it might be a long match, I think that Wawrinka will win this match with at least 4 games in his advantage. My prediction for this is Wawrinka -3.5 games will win.