Description:Leaders Bayern Munich demolished Schalke 04 4-0 with two goals from Austria international David Alaba to keep their title charge on track and open a 15-point gap at the top of the Bundesliga on Saturday. Left back Alaba scored either side of a sensational Bastian Schweinsteiger free kick with Mario Gomez, starting ahead of top scorer Mario Mandzukic, drilling in the fourth as Bayern made it four straight wins this year without conceding a goal.(2:59)