I've tried it online too, the exact same thing happened. Bounced off the bar onto keepers back then in the net

i try it a lot, but only managed to score once.
You have to shoot with the "lob/cross" button, not the "shoot" button. Fill the power bar, and you will get it on target 75% of the time (Usually hitting the bar or the keeper punching it over for a corner) It depends what player you use to shoot though. Eduardo is very good at 'em, as he's left footed.