With the 'Klassiker' clash against Bayern Munich on the horizon, Borussia Dortmund will want to avoid a loss of focus against Cologne on Sunday with a title on the line. 

While Dortmund have had their share of woes against better sides in recent years, their title challenges have truly come undone in poor performances against the league's outmatched but spirited underdogs.

Led by pugnacious manager Steffen Baumgart, often seen on the sideline sporting just a flat cap and a t-shirt in the German winter chill, no club matches the plays the underdog with more spirit than Cologne. 

Dortmund have stuttered after their barnstorming start to 2023, chalking up 10 wins in 10 matches, came to an end with a 2-0 defeat at Chelsea, resulting in a 2-1 elimination from the Champions League.

That loss was followed by a 2-2 draw at struggling derby rivals Schalke, as an outgunned but dogged home side equalised twice.

A return to winning by Dortmund on Saturday would lift them a point clear of Bayern Munich atop the Bundesliga table, for at least one night. 

Bayern travel to Xavi Alonso's unpredictable Bayer Leverkusen on Sunday. 

Dortmund's next match after Cologne is against Bayern. 

Dortmund have not won a league match in Munich since the 2013-14 season, when Jurgen Klopp was still in charge, one reason they have been perennial German football bridesmaids since their last title in 2012.

When Dortmund visited Cologne in October they had a chance to go top but, despite taking an early lead, lost 3-2. 

That result was in Dortmund boss Edin Terzic's mind on Thursday when he said "we have been warned enough" about Cologne 

Cologne are on a run of poor form but know another result against a title challenger could put them back on course. 

After starting 2023 with a five-match unbeaten run, including a draw at Bayern, Cologne have lost three of their past four without scoring, giving rise to fears the 12th-placed side may be drawn into a relegation battle.

Baumgart said his side partied a little too hard during Cologne's famous Carnival celebrations in February and are paying the price.

"I don't want to offend anyone, but I have now had my experience with the carnival," the manager, who joined Cologne during the Covid pandemic, said on Thursday.

"That wasn't good for us. 

"In the future, I will try and do things differently."

One to watch: Benjamin Pavard (Bayern Munich)

The France defender's recent turnaround has mirrored that of his club, who now sit two points clear atop the Bundesliga table.

Bayern stumbled after the Bundesliga's winter break but has now re-established their dominance in the league and in Europe.

After scoring his second in Bayern's 5-3 win over Augsburg -- his first brace in professional football -- Pavard faced the stands and tapped his badge, a sight unthinkable in January when rumours swirled that the World Cup winner wanted out. 

Pavard confirmed his committment in early March, saying Bayern "can achieve great things this season" and "I'm not leaving the ship in the middle of the journey".

Key stats

6 - Bayern Munich's Sadio Mane has had six goals ruled out for offside this season, the most of any player in the top five European leagues.

0 - Hoffenheim were the only club in the bottom five to lose last round and are dead last on 19 points.

6/7 - Bayern have won six of their last seven against Leverkusen, a run of victories that includes the 2020 German Cup final.

Fixtures (all times 1430 GMT unless otherwise stated)

Friday

Borussia Moenchengladbach v Werder Bremen (1930)

Saturday

Augsburg v Schalke, Hoffenheim v Hertha Berlin, Stuttgart v Wolfsburg, Bochum v RB Leipzig, Borussia Dortmund v Cologne (1730)

Sunday

Union Berlin v Eintracht Frankfurt, Bayer Leverkusen v Bayern Munich (1630), Mainz v Freiburg (1830)