Al Hilal's surprised every one because ppl didn't expect Manchester City to lose. Their win against a premier league team shows SPL teams are strong they aren't going to give up they'll play trying to win. Al Hilal won't win the cup but they've made SPL teams proud of them.
Man City isn't in their stable performance since the last season, some people probably aren't so surprised to see their lose. However, it is amazing that Al Hilal can beat Man City, it indicates a team from Saudi league quite strong to face the European teams. Even a big team from EPL, can be defeated by Al Hilal, it is a good sign of the Saudi league quality level.