Bundesliga leaders Bayern Munich face Borussia Dortmund on Saturday with relations between the German heavyweights seemingly at an all-time low.
The atmosphere between the clubs soured since Bayern began snapping up Dortmund players two years ago, with Mario Goetze becoming the first of a successful Dortmund team to leave for their league rivals.
Long before striker Robert Lewandowski joined the Bavarians this season, a war of words erupted between club bosses.
With Dortmund winger Marco Reus triggering the interest of Bayern, and club CEO Karl-Heinz Rummenigge saying this week they "might be potentially interested" in him, ties have never been so strained.
Club bosses will again skip the traditional pre-game lunch to avoid each other, while Dortmund sports director Michael Zorc rejected the latest Bayern advance for Reus as just another "distraction."
"We are not paying any attention to what comes out of Munich. It is repetitive after all," he said.
It is not the first time Bayern have made open advances for German international Reus but the timing is important as troubled Dortmund are under pressure to start delivering in the league.
They are in 15th place, a full 14 points behind Bayern, after losing six of their nine league games.
A 3-0 victory over St Pauli in the German Cup on Tuesday offered some respite for coach Juergen Klopp, with under-fire striker Ciro Immobile scoring once and setting up another.
Dortmund's defence also looked to be gradually find its stability with Mats Hummels and Neven Subotic resuming their central partnership and Sokratis Papastathopoulos effective in his new role as full back.
Fans are also fully behind the team with one woman making a public declaration of love during the post-game news conference on Tuesday.
"You led us to success and we will lead you through the crisis," she told a smiling and embarrassed-looking coach Klopp, before he stood up to hug her.
Klopp will need all the support he can get against Bayern, who are undefeated in the three competitions they are still in this season.
Dortmund beat them in the German Super Cup in August but that seems like a lifetime ago.
Bayern have continued to improve over the past few months and are now four points clear at the top.
With Franck Ribery back to full fitness and fellow winger Arjen Robben, who sat out their 3-1 German Cup win over Hamburg SV on Wednesday, also expected to return to the starting lineup, Bayern are the odds-on favourites.
"When you look at the table then no," said Bayern midfielder Thomas Mueller when asked whether the teams had similar quality. "But they do if you look at the difficulty factor.
"Dortmund are always an uncomfortable opponent. Maybe it is even easier for them than when they face other teams because they know exactly what plan to follow against us.
"I don't expect we will be leading 5-0 at halftime. There have been a lot of tight games in the past years between but if we keep our cool and avoid their quick breaks then we will look good."
OPTA HEAD-TO-HEAD STATS
OPTA MATCH FACTS
Only two teams have won the Bundesliga title more than once over the past 21 seasons: Bayern (12) and Dortmund (5), who have won 17 of those 21 championships between them.
FC Bayern are without a Bundesliga home win against Dortmund in their last four attempts (D1 L3).
The last time Dortmund were as low in the table (currently 15th) going into a meeting with Bayern was in November 1987 - they were 16th back then. BVB beat the second-placed FCB 3-1 away from home.
Dortmund have just seven points on the board after nine games, their worst record in 29 years. BVB have only been worse off twice before, in 1984/85 and 1985/86 (6 points each time when converted to the 3-points-per-win system).
FC Bayern are unbeaten in their last 13 Bundesliga games (W10 D3), the longest run of its kind in the top flight at present. Their last league defeat was a 3-0 loss to Dortmund on matchday 30 last season.
BVB have lost each of their last four matches, something that last happened in the league in March/April 2000 (a run of 6 straight defeats).
Dortmund have collected more points from their three Champions League games (9) than they have from their nine Bundesliga fixtures (7).
No side has suffered as many defeats as BVB this season (6). No team has recorded as many wins as FCB (6).
Bayern are the only side yet to concede a first-half goal in the Bundesliga this season. Including the last campaign, FCB haven't let in a goal before the break in any of their last 11 top-flight matches.
Robert Lewandowski played for BVB between 2010 and 2014 and netted 103 times for Borussia in 187 competitive matches. Mario Goetze wore Dortmund colours between 2001 and 2013 and made 83 Bundesliga appearances for BVB (22 goals).