• FC Schalke 04 and Borussia Dortmund face off on Matchday 29 at the Royal Blues' VELTINS Arena.
• Revierderby one of the ultimate fixtures on the football calendar.
• Read on for the lowdown on the Ruhr district's fiercest rivalries.
Whatever the relative current fortunes of these two Bundesliga heavyweights in the grander scheme of things, this championship-within-a-championship operates to its own autonomous rules - not least for the massed ranks of their respective fans.
For many diehards, the result of this one can make or break an entire campaign, and while the players are professionally obliged to maintain the one-game-at-a-time mantra, they will also savour the ultimate German derby for the unique occasion that it is.
Tradition, regional politics and fierce local pride once again go into the pot on Matchday 29, but not before bundesliga.com looks back on some of the most memorable Ruhr rumbles of seasons past.
Dortmund took eight of the first ten derby dates of the Bundesliga era before Die Knappen finally struck gold on 20 April, 1968, with their first win over Dortmund since 7 September, 1963. Another Schalke success on 4 March, 1972, proved an even more bitter pill to swallow for Dortmund, whose subsequent relegation ensured it would be another three years before the Ruhr powerhouses could renew acquaintances.
True to form, it was Dortmund who restored Kohlenpott order upon their return to the top-flight as Lothar Huber gave Dortmund their first victory over Schalke in nearly ten years on 5 November, 1977. However, it was not until August 1991 that the real fireworks between the two began.
Returning to the Bundesliga after their 1987/88 relegation, Schalke and former Dortmund midfielder Ingo Anderbrügge set the tone with the opening goal at the former's old Parkstadion home just two minutes into the game. Dortmund managed to draw level before half-time, but were left reeling after the restart as the Royal Blues cruised to a stunning 5-2 win with Dortmund ultimately losing out in the title race to eventual Bundesliga winners VfB Stuttgart on goal difference.
Schalke, or rather goalkeeper Jens Lehmann, would steal the headlines yet again on 19 December, 1997, when the former Germany international rose to head home in the 90th minute in a thrilling 2-2 draw, and in the process became the first-ever goalkeeper to score a goal from open play in the Bundesliga. Dortmund were then served a wicked dose of déjà vu seven years later, courtesy of Ebbe Sand's last-gasp strike on Dortmund soil in December 2004.
Dortmund would have their revenge, though, ending Schalke's 12-match unbeaten Revierderby run in front of 61,500 fans at the Gelsenkirchen Arena on 14 May, 2005. Sebastian Kehl and Lars Ricken netted in the 2-1 win, but Dortmund's next victorious effort would taste even sweeter in what became known as the 'Mother of all Derbies'.
On the penultimate day of the 2006/07 season, Schalke went into the clash as league leaders, a point clear of second-placed Stuttgart. The Swabians won their Matchday 33 encounter in Bochum, but Schalke went down at the SIGNAL IDUNA PARK with Alexander Frei and Euzebiusz 'Ebi' Smolarek the party poopers. Frei was again the chief culprit on 13 September, 2008, grabbing a second-half brace as Schalke squandered a 3-0 lead on Dortmund's own patch in a game that remarkably ended 3-3.
Form books favour Dortmund
Jürgen Klopp's Dortmund effectively cleaned house in the Ruhr en route to back-to-back titles in 2010/11 and 2011/12, but in another twist of fate, Die Knappen completed a rare Bundesliga double over their Schwarz-Gelben nemesis in 2012/13.
Schalke have won only one of their five derby match-ups since, however, and with Thomas Tuchel's title chasers unbeaten in 2016, it is going to take a gargantuan effort to prevent BVB from painting the Ruhr region black and yellow this weekend.