We did,but that's just one game.Margin between top sides and other teams in La Liga is much bigger.And it was always like that,even when Real and Barca weren't that good teams.
It's quite staggering. Their dominance gets seldomly broken. Simeone did it once in 13/14, the last guy before that was Benitez with Valencia, who actually did it twice in 01/02 and 03/04.