Even missing several stars, Bayern Munich proved they can win ugly, Borussia Dortmund posted another big victory and Werder Bremen became the first club to sack their coach this season.

Here are five things we learnt from week three in the Bundesliga:

Illness to defenders Philipp Lahm, David Alaba, Mats Hummels and forward Thomas Mueller meant Bayern coach Carlo Ancelotti rang the changes for Saturday's 3-1 comeback win against Ingolstadt.

Paraguay striker Dario Lezcano scored after just eight minutes, but goals by Robert Lewandowski, Xabi Alonso and Rafinha preserved Bayern's 100 percent record.

Ancelotti praised his side's character, but Germany captain Manuel Neuer, rock solid in Bayern's goal, was their hero.

He twice denied Ingolstadt's Mathew Leckie from close range, including a superb save just after the break, as the visitors created 13 chances, compared to Bayern's ten.

"Thank god we have Manuel Neuer in goal," said Rafinha.

Fresh from Wednesday's 6-0 Champions League drubbing of Legia Warsaw, Borussia Dortmund ran up another tennis score in their 6-0 hammering at home to Darmstadt.

The 12 goals from 10 different players came after coach Thomas Tuchel left stars Mario Goetze and Pierre-Emerick Aubameyang on the bench against Darmstadt.

"It would be nice if a 6-0 win becomes our standard result," quipped Dortmund's Germany midfielder Julian Weigl.

Their shock 1-0 defeat at newly-promoted RB Leipzig last weekend means Dortmund have six points from a possible nine.

Tuchel warns they face tougher challenges at Wolfsburg on Tuesday and Freiburg at home on Friday before hosting Real Madrid in a plum Champions League group stage tie on September 27.

"We were clear favourites (against Legia and Darmstadt) and will be tested on Tuesday and Friday," said Tuchel.

Viktor Skripnik became the first German league coach to be sacked this season after Werder Bremen leaked three goals in 21 minutes in their 4-1 defeat at Borussia Moenchengladbach.

The result was the final straw for Bremen's bosses and Skripnik's two-year tenure was ended on Sunday after his team had leaked 14 goals over four consecutive defeats -- the worst start to a season in the club's history.

Under-23 coach Alexander Nouri will stand-in as first team coach until a successor is found for the league games at home to Mainz on Wednesday and Wolfsburg away on Saturday and top priority is fixing the leaky defence.

Red Bull-backed RB Leipzig are unpopular with German fans for the commercialism they represent, but Ralf Rangnick's young guns carved out another impressive result with a 4-0 win at Hamburg with four second-half goals.

"We lost 4-0 to Leipzig, that says it all. I'm sorry for each of us who had to wear our colours today," fumed Hamburg's Germany midfielder Lewis Holtby.

Formed in 2009, Leipzig earned their Bundesliga place with four promotions in seven years.

Having drawn 2-2 at Hoffenheim on their debut in Germany's top flight, Leipzig shocked Borussia Dortmund 1-0 last weekend in their first home game.

With seven points from their first three games, they face a test at home to Champions League side Borussia Moenchengladbach on Wednesday.

Christian Pulisic turned 18 on Sunday and Borussia Dortmund's USA international showed his junior years by revealing he was celebrating an outstanding week on the pitch with tickets to see Justin Bieber in concert.

He became Borussia Dortmund's youngest player in the Champions League when he started in the 6-0 away victory over Legia Warsaw on Wednesday, then netted in Dortmund's 6-0 drubbing of Darmstadt in the Bundesliga.

"It was definitely a good early birthday present to get the goal," Pulisic told Bundesliga.com.

"I'm very excited to go with my friends (to see Justin Bieber) on my birthday."