Union Berlin's fairytale run at the top of the Bundesliga continued Sunday after a howler from Borussia Dortmund goalkeeper Gregor Kobel helped them to a stunning 2-0 win over Edin Terzic's side. Two first-half goals from Janik Haberer put Union into dreamland as they extended their five-week run at the top of the table and inflicted a fourth defeat of the season on Dortmund. The visitors got off to a nightmare start after Kobel handed Union the opener on a silver platter. As he stepped up to receive a routine backpass from Raphael Guerreiro, Kobel slipped on the grass in his own penalty area, allowing Haberer to tap the ball into the empty net.