In the black-and-yellow corner, the last team to beat the mighty Bayern Munich to the Bundesliga title: the dazzling daredevils of Borussia Dortmund. And in the green-and-white corner, a 1970s giant once again bestriding the German top flight like a colossus: the free-flowing Foals of Borussia Mönchengladbach. Welcome to the Battle of the Borussias.

The two challengers came in to the 2018/19 season boasting five Bundesliga titles apiece, joint-second in history but a world away from undisputed heavyweight champions Bayern and their 27 crowns. Yet Germany's most successful club have found themselves battered and bruised by the Borussia storm so far this term, going down 3-0 to Gladbach at the Allianz Arena and twice squandering the lead to lose 3-2 in a memorable Klassiker in Dortmund.

Following their fearless start to the campaign, the two Borussias now sit proudly in first and second place in the table, with leaders Dortmund four points clear of Gladbach, seven ahead of third-placed Eintracht Frankfurt, and nine clear of champions Bayern.

Could this be the year when one of the Borussias gets their hands on a sixth Bundesliga title, to move ahead of their namesakes into outright second on the all-time list? As we head into the final stretch of the Hinrunde – which concludes with their highly anticipated meeting at the Signal Iduna Park, bundesliga.com takes a closer look at what's making BVB and BMG tick…

Fearsome firepower: Alcacer & Plea

Goals are the most precious commodity in football, so it's no surprise to see that Dortmund and Gladbach have racked up more of them than any of their rivals this season.

Leaders BVB have scored a whopping 35 after 12 matchdays, an average of just under three per game and their best tally at this stage since the inaugural Bundesliga season of 1963/64. No other squad boasts as many goalscorers – 15 of their players have found the back of the net – while Paco Alcacer (nine) and Marco Reus (eight) have accounted for almost half of their league total. Incredibly, over a third of those goals (12) were scored by substitutes.

Watch: Alcacer's game dissected

"It really helps the team when we have such good players coming off the bench," said Lukasz Piszczek, who fired in a spectacular late winner at Mainz on Matchday 12. "It gives us all that extra push, it's such an important attribute." 

Dieter Hecking's Gladbach have also been scoring for fun, hitting 30 goals so far in 2018/19. As well as putting three past Bayern in Munich, they grabbed four in big home wins over Mainz and Hannover. Thorgan Hazard and Alassane Plea lead the way with eight apiece, while Jonas Hofmann has also played his part with five, including a first career hat-trick in that victory against the 05ers. In total, 10 Foals players have been on target in the Bundesliga this term.

Leaders of the pack: Reus & Hazard

Dortmund and Gladbach are bursting at the seams with talent at both ends of the pitch, but two men in particular have stood out as the clubs have embarked on their quest to conquer the Bundesliga: Reus and Hazard.

Plagued by injuries in recent years, Reus has flourished since being reunited with Lucien Favre, the coach who gave him his big break in 2011… at Gladbach. The Swiss tactician made the savvy move of entrusting Reus with the captain's armband, and he has more than repaid that faith. As well as contributing eight goals and five assists, the 29-year-old attacking midfielder has been the driving force behind BVB's best start to a season since 2010/11.   

"Marco is an experienced player now and as a captain, he must be a role model for others," Favre said. "The team and I count on him to do his job well on and off the pitch."

Hazard, meanwhile, has been the chief danger man for Gladbach. Like Reus, the Belgium international has had a hand in 13 goals, scoring eight and setting up another five. Just as his older brother Eden has lit up the English Premier League, so Thorgan is setting fire to the Bundesliga, having emerged as one of the most talented creative players in the German top flight. The 25-year-old is now a vital cog in the Gladbach machine.

Watch: Analysing Hazard's game

"Thorgan has been with us since 2014 and has continued to progress, especially this season," Gladbach sporting director Max Eberl recently told kicker. "He has become more decisive in goal-scoring situations and his sense of positioning has improved. He is a complete team player who also puts a lot of effort into getting back to defend."

Home comforts: Fortress Signal Iduna & Bastion Borussia-Park

Both sides have built their successful campaigns so far on excellent home form. Nowhere has this been better illustrated than at the Borussia-Park, where Gladbach have picked up six wins in as many league outings. The Foals are the only team in the Bundesliga with a perfect record in front of their own fans, and that's after hosting heavyweights like Bayer Leverkusen, Schalke and Frankfurt.

Dortmund have only dropped two points at the Signal Iduna Park, after conceding a late Salomon Kalou penalty to draw 2-2 with Hertha Berlin on Matchday 9. Otherwise they have got the better of all comers, including RB Leipzig, Frankfurt and Bayern. As for Nuremberg, they left North Rhine-Westphalia with their tails between their legs on Matchday 5, after BVB romped to a 7-0 victory.

The only remaining unbeaten side in the Bundesliga, Dortmund hadn't won on the road in over seven months until they came from two goals down to stun Leverkusen on Matchday 6. Since then, the leaders haven't looked back, stringing together four wins in their last four away games. How local rivals Schalke would love to be the ones to end that run in Matchday 14's Revierderby at the Veltins-Arena.

Gladbach have been a little more irregular away from the Borussia-Park, with two wins, two draws and two defeats. One of those victories was at the Allianz Arena, admittedly, but the Foals also lost in Berlin and Freiburg. Between now and Christmas they will travel to Leipzig, Hoffenheim and Dortmund, which should provide a thorough test of their title credentials.

Smart signings: Hakimi, Lang & the supporting cast

The new kids on the Borussia block have also made a decisive impact since arriving this summer. Chief among them are Dortmund's Alcacer and Gladbach's Plea, who are both in the running for the Torjägerkanone in their maiden Bundesliga season.

Alcacer has redefined the word 'supersub' since arriving in Germany, scoring eight of his nine goals from the bench. The Spaniard is only one strike off the single-season record heading into December. Such has been the 25-year-old's impact since his summer loan move from Barcelona that Dortmund have already made the deal permanent, securing Alcacer's services through to June 2023.

"Paco is wholeheartedly with us, he has settled in quickly and become an integral part of our squad," enthused BVB sporting director Michael Zorc. "He's a real scorer of high footballing quality and has already decided some important games for us. We look forward to many more goals and assists from Paco in the coming years."

Plea has also taken to the Bundesliga like a duck to water, netting eight goals and providing three assists. The former Nice man's efforts earned him a first cap with France during the November international break, as a late substitute in the friendly win over Uruguay. 

"We're a great bunch and it's working for us at the moment," the 25-year-old striker told the Gladbach website, after netting his first Bundesliga hat-trick in a 3-1 win at Werder Bremen. "I have nothing but praise for my teammates, they've welcomed me in and I really feel part of the team. I just want to help them out with my goals and bring success to this club."

Alcacer and Plea aren't the only new recruits who have been shining. Axel Witsel and Thomas Delaney have helped to beef up Dortmund's midfield, while centre-back Abdou Diallo and full-back Achraf Hakimi – on loan from Real Madrid – are among the first names on Favre's teamsheet. Over at Gladbach, Michael Lang has established himself as Hecking's first-choice right-back since arriving from Basel, and even opened his account in the 4-1 win over Hannover.

Young guns blazing: Sancho & Neuhaus

Both Favre and Hecking have also shown a willingness to give their talented young players a chance, which has become something of a Bundesliga hallmark in recent years. Winger Jadon Sancho is one of the most exciting talents to come out of England for some time, and the BVB star has been proving it week in, week out, notching four goals and a league-high six assists. He will turn 19 in March.  

Hakimi celebrated his 20th birthday at the start of November, and the Morocco international has also enjoyed a breakout campaign, contributing a goal and three assists and showing he is equally comfortable at left-back or right-back. Christian Pulisic's talent is no longer a secret to anybody in the Bundesliga or beyond, while fellow 20-year-old Jacob Bruun Larsen also offers plenty of attacking menace from out wide. The scary thought? All of these precocious hotshots still have room for improvement.

Watch: A closer look at Sancho's game

"You have to remember that these young players still need time to mature," Favre warned. "There are still many details to improve."

Gladbach also have a number of flourishing young Foals in their stable, notably Florian Neuhaus. The 21-year-old spent last season earning his stripes with Fortuna Düsseldorf – helping them win promotion back to the Bundesliga – and now looks closer to the finished article; a chance-creating midfielder reminiscent of former Bayern man Toni Kroos. The Germany U21 international has featured in every league game so far, pulling the strings at the heart of the Gladbach midfield and providing, like Sancho, a league-leading six assists.

Christmas cracker: 21 December 2018

With such a wealth of talent on both sides of the Rhine, the Battle of the Borussias could be one that rumbles on into 2019 and through to the business end of the season. First, though, it will be fascinating to see who comes out on top when the two sides face off in Dortmund four days before Christmas, in the blockbuster opening encounter of Matchday 17.

Lauded for their attacking prowess, BVB and Gladbach also boast two of the Bundesliga's best defensive records, having conceded 13 and 14 goals respectively – only Leipzig have been meaner at the back, shipping just 10 goals. So no doubt all eyes will be on the Signal Iduna Park when an unstoppable Borussia force meets an immovable Borussia object.

It could be another memorable stepping stone on the path back to Bundesliga glory. While most Dortmund fans remember the back-to-back titles of 2011 and 2012, it was all the way back in 1977 that Gladbach last lifted the Meisterschale when they went one better with a third consecutive honour. Let battle commence.

Click here for more Bundesliga news and features!