What do you base this on? Portugal never lost by two goals in the qualifiers, let alone "at least" two goals.
On the flipside, Ghana only blows out crappy African teams. They've arguably had the better of two games now, and failed to win. Forget about winning by two -- they haven't won period. Even in a US game where they clearly had ridiculous time on the ball.
This is either going to be a one-goal win or a tie.
Portugal are front runners. Portugal have 0 fight in them. Portugal ain't the type to put their head down and put in work. Factor in the injuries, less rest, playing in the Amazon, and they already said a tie was no different to a loss, Ghana wins unless Portugal muster some fight.
Their reaction last night said it all. Instead of seeing as a life line Ronaldo and their manager headed straight back to the locker room. There was no reaction from any of them.
Are Portugal gonna risk Ronaldo in what they see as a meaningless game? Ghana just has to not be too aggressive and leave a shaky defense even more exposed.