The Bundesliga's first- and third-placed teams face off on Saturday as league leaders Bayern Munich visit the BayArena to take on Leverkusen.
The Bavarian giants have built a commanding 20-point lead over second-placed Dortmund in the league table and could theoretically wrap up the title by month's end.
Indeed, Bayern have been nearly unstoppable this season. The one blemish on an otherwise sparkling Bundesliga campaign is a 1-2 home loss on October 28. Incidentally, their opponents on that day were Leverkusen.
The Werkself beat Champions League winners Chelsea last season, and they now have a chance to do the double against one of this season's favorites to win Europe's most coveted club trophy. They will play at home, but it will be a very difficult task nonetheless against a Bayern side that have conceded just once away from home, and are undefeated with 11 wins in 12 matches on the road.
There will be some key battles in store on the day, the outcomes of which could well decide the game. Read on for an analysis of the most important head-to-head contests.