Leon Goretzka returned from a long injury lay-off to score in Bayern Munich’s 4-1 win in Freiburg on Saturday which put the champions nine points clear in the Bundesliga as Borussia Dortmund collapsed at home to RB Leipzig. Leipzig stormed to a 4-1 victory at Dortmund, confirming their turnaround under coach Domenico Tedesco, and left Bayern cruising towards a 10th consecutive title. There are six games remaining this season but, even including Bayern hosting second-placed Dortmund on April 23, that looks a formality for the serial champions. Germany midfielder Goretzka headed Bayern ahead in …