Former Bayern Munich coach Ottmar Hitzfeld says Borussia Dortmund will remain second best in the Bundesliga for years to come regardless of the outcome of Saturday's Klassiker.
Bayern's quest for a fourth successive Bundesliga title was dented with a surprise 2-1 defeat to Mainz on Wednesday, Thomas Tuchel's Dortmund beating Darmstadt 2-0 to close the gap at the top to five points.
Dortmund are the only side to have broken Bayern's dominance in the last six seasons - winning back-to-back titles under Jurgen Klopp in 2011 and 2012.
Victory for Tuchel's side at Signal Iduna Park on Saturday could set up a thrilling final few weeks of the campaign but Hitzfeld, who won the title twice at Dortmund and five times in two spells with Bayern, believes the Bavarians will remain a class apart.
"I don't know what position Borussia Dortmund would finish in England, Italy or Spain. But here in Germany you have one of the best clubs in the world - Bayern Munich," he told Omnisport.
"They are on the same level as Real Madrid or Barcelona. There is a clear hierarchy in the Bundesliga. That won't change in the next few years.
"At this time you can't see Wolfsburg or Gladbach or Leverkusen or Schalke taking Dortmund's place. There is no need to talk about Bayern, they are in a different dimension.
"Dortmund are the second force in Germany and have been over the past years. And I am sure that they will stay in this position for the next years."
Tuchel has enjoyed an impressive start to life at Dortmund, following the club's struggles during Klopp's final campaign.
With Bundesliga, DFB-Pokal and Europa League titles still to play for, Hitzfeld added: "Thomas Tuchel is a coach who can work in the long-term.
"He has integrated himself perfectly. He came to Dortmund with a clear concept and was well prepared. The team is a lot more flexible. They can play with a lot of possession, not just with a full attack and speed.
"They can also play with wingers, exhausting their opponents. That's where Dortmund have become a lot more flexible under Thomas Tuchel."
