The gritty Spaniard put in another determined display, breezing through the first set and clinching the second-set tiebreak with a blistering ace down the centre line.
French Open champion Ferrero, who hurt his shoulder and elbow in his previous match against Italian Filippo Volandri, suffered a let-down in the third set as Johansson took it on another tiebreak.
But a fired-up Ferrero broke in the seventh game of the fourth set and wrapped up proceedings on his first match point, forcing his opponent into a wild forehand after two hours, 28 minutes.
