FC Saarbrucken boss Rudiger Ziehl says it would be "crazy" to stop his third-tier minnows "dreaming" of completing a fairytale run to the German Cup final.

The underdogs have upset Bayern Munich and two other Bundesliga clubs, Borussia Monchengladbach and Eintracht Frankfurt, to make the DFB-Pokal semis.

They face second-tier FC Kaiserslautern on Tuesday for a place in the final.

"It's totally normal to have thoughts about the final because you are close," Ziehl told BBC World Service Sport.

"It's crazy to forbid dreaming - this is a great moment and the days before you are maybe dreaming, thinking about a final in Berlin."

Bundesliga leaders Bayer Leverkusen, seeking a league and cup double under Xabi Alonso, or Fortuna Dusseldorf will await the winners in May's final at the Olympiastadion.

"It's something special for a third-league club to be in the final and you can't say 'don't think about it'," added Ziehl, 46.

"After this game, if we are successful, we will have [achieved] something that is such a big, big thing and, for sure, everybody's thinking about it."

Historically, Saarbrucken, based right on the German border with France, are no strangers to punching above their weight.

Die Molschder have only spent five seasons in the Bundesliga in their 120-year existence but were one of Germany's two representatives in the very first European Cup in 1955-56.

They beat Italian giants AC Milan 4-3 away - but lost the return leg 4-1 - in what was arguably the most famous result in the club's history.

The most famous result until last November, that is - when Thomas Tuchel's Bayern side were humbled by Marcel Gaus' 96th-minute second-round winner at Saarbrucken's Ludwigsparkstadion.

England captain Harry Kane was an unused substitute that evening but it was still a strong Bayern line-up including Manuel Neuer, Leroy Sane and Thomas Muller, plus several other first-team regulars.

"The whole stadium was exploding," recalls Ziehl, who took over at Saarbrucken in 2022.

"Everything was just so crazy when we scored and I think everybody will keep this in their heads for their whole lives.

"Winning against Bayern Munich as Saarbrucken, a third-league team, it was a big, great party in the whole city."

But did Ziehl truly believe his team could shock one of the biggest and best sides in Europe, let alone Germany?

"You have to believe in your team, I think that is a very big thing as a coach," he said. "You must be the first one to say 'we can win this game'.

"Everybody knows in a normal game, for sure Bayern win. But I told the team we will have our moments, we have to defend, fight, run like crazy and maybe there's a little, little chance."

Saarbrucken are developing a reputation as German football's giant-slayers - astonishingly, this is their second run to the DFB-Pokal semi-finals in four years.

They became the first fourth-tier team to ever reach the last four in 2019-20, shocking two top-flight sides, FC Koln and Dusseldorf, on the way to the semis, where they fell 3-0 to Leverkusen.

But this season's run has surpassed even that in terms of upsets, with Frankfurt and Monchengladbach following Bayern in falling to the minnows.

"The secret is hard to explain, maybe you can't explain it. It's like a dream right now," added Ziehl, whose side sit mid-table in 11th in 3. Liga.

"One point for sure is the team spirit, the mentality - we have it through the season and especially in these amazing cup games."

Now Kaiserslautern, who Ziehl turned out for in the Bundesliga during his playing career as a defensive midfielder, stand in his and Saarbrucken's way.

However, Saarbrucken, who count former Leeds hero Tony Yeboah and ex-USA winger Eric Wynalda among their most illustrious former players, will enjoy home advantage for the fifth round running.

"Every game against a second-league or first-league club for us must be a perfect match from our side," Ziehl admitted.

"So many things have to come together so that we can win the game - we had this now three times against first-league clubs. It will be a difficult game, we need the same things we needed before."