Borussia Dortmund took an early lead against Schalke but finished the Revierderby with nine men and their Bundesliga hopes in tatters.
Nine-man Borussia Dortmund collapsed to a nightmare 4-2 Revierderby defeat against bitter rivals Schalke, leaving Bayern Munich as strong favourites to win a seventh consecutive Bundesliga title.
Lucien Favre's side looked set to keep their bid for glory on track when Jadon Sancho brilliantly created Mario Gotze's early goal but Daniel Caligiuri converted an 18th-minute penalty.