'Only Union will be German champions!'

As the players applauded their home supporters at full-time, one chant resonated more loudly and clearly than any other around the stadium: "Deutsche Meister wird nur der FCU!" — "Only Union will be German champions!"

These are heady days for Union Berlin. Four home wins from five and they comfortably outplayed Borussia Dortmund on Sunday to go four points clear at the top of the Bundesliga. It's only mid-October but could we be witnessing the start of a Bundesliga miracle? Surely not.

All of the ingredients are there though: champions Bayern Munich have underperformed in the league and the likeliest candidates to challenge them — RB Leipzig, Bayer Leverkusen, and Dortmund themselves — are stuttering too. Enter the underdog. Union are a team in the truest sense of the word, greater than the sum of its parts, and coached by Urs Fischer to play one way exceptionally well.

"Everyone knows what to do in every situation," Union midfielder Rani Khedira said after the game. "It almost doesn't matter how the opponent plays."

Could Union Berlin 'do a Leicester'?

Without wishing to get too excited about the still-outlandish prospect of a new Bundesliga winner for the first time in a decade, some faint parallels with Leicester City's miracle title-winning season in the Premier League are starting to appear: a team that defends as a collective, ruthlessly efficient in attack, and coached to excel within a singular strategic blueprint.

In a season when all but a few of Union's players will be staying at home while rival players gear up for the intensity of a mid-season World Cup, Union will pick up in January rested and raring to go. The Bundesliga's other surprise challengers, Freiburg, will enjoy a similar advantage too.

The first target for Union, only promoted to the top-flight in 2019, is to get to the World Cup break still at the top of the tree. So far, so good, but as you'd expect, Fischer isn't getting ahead of himself, even with their next game an outing to bottom side Bochum.

"The league position is extraordinary," Fischer reflected, before returning to script: "...but it is just a snapshot."

Dortmund tactically trumped

Union were gifted the best possible start against Dortmund when goalkeeper Gregor Kobel's calamitous slip as he attempted to clear the ball let in Janik Haberer for a tap-in after seven minutes. A jittery Dortmund, playing three at the back to accommodate Niklas Süle into the backline and give Raphael Guerreiro and Thomas Meunier license to get forward, always looked exposed on the break. Jude Bellingham and Emre Can were swamped every time Andras Schäfer or Haberer mounted a Union breakaway.

Dortmund coach Edin Terzic switched things up at the break, moving to a more attacking formation but the damage was already done. Dortmund were tactically trumped by a slicker and better drilled team, and while the opener may have been lucky, this wasn't a defeat that Dortmund can feel aggrieved about. There's no hiding from the fact that while they're only three points off second, they languish in eighth following their worst start in the league since 2014/15. For them, the title has rarely looked further away.

Union revel in the dirty work

After Haberer's silky second had sealed the deal, Union rolled up their sleevs and defended resolutely until they were over the line. Every second half save by Union goalkeeper Frederik Ronnow was celebrated like a goal — this is a team and a fanbase that appreciates the dirty side of the game as much as the craft.

The DFL's chief executive Donata Hopfen has been vocal about her desire to make the Bundesliga more competitive and has even floated end-of-season playoffs to make the top end of the league less predictable. As she watched on from the soft seats in Berlin, she may just have to put those plans on ice.

Edited by: Matt Pearson