Managerless Bayern Munich thrashed Borussia Dortmund 4-0 in ‘Der Klassiker’ on Saturday as Robert Lewandowski continued his phenomenal scoring run with two goals at the Allianz Arena.

Lewandowski’s first-half header and 76th-minute tap-in mean he has scored in all of Bayern’s Bundesliga and Champions League games this season for a tally of 23 goals.

“We were very focused, we knew we had to give 100 percent and improve,” said Lewandowski after the reigning Bundesliga champions bounced back emphatically from last weekend’s 5-1 drubbing at Eintracht Frankfurt.

Serge Gnabry claimed Bayern’s second, while visiting captain Mats Hummels scored a late own goal for his former club as Dortmund suffered another heavy defeat in Munich after a 5-0 rout in April.

“After 10 minutes, we made it clear that we wanted to win,” said Bayern forward Thomas Mueller. “The alibis had all been used up.”

Bayern moved up to third, level on points with second-placed RB Leipzig and one behind leaders Borussia Moenchengladbach, who host Werder Bremen Sunday.

Interim coach Hansi Flick enjoyed his second win in charge since Niko Kovac was sacked last Sunday.

“It’s not been easy for the team, we didn’t have that many training sessions,” said Flick.

“They knew they had a duty to improve and they did.”

Afterwards, club chairman Karl-Heinz Rummenigge said Flick will stay in charge for Bayern’s next game on November 23 at Fortuna Duesseldorf.

However, Bayern are having difficulties finding a new coach, with Arsene Wenger on Saturday contradicting their claims they turned him down as Kovac’s successor and slammed the club for a lack of discretion.

Ajax coach Erik ten Hag and Paris Saint-Germain boss Thomas Tuchel have already made it clear they will not join Bayern this season.

Despite their off-field troubles, Bayern dominated as Lewandowski opened the scoring with a superb header from a Benjamin Pavard cross on 17 minutes.

Dortmund winger Jadon Sancho was taken off on 36 minutes after failing to make an impact on proceedings.

Gnabry had a goal ruled out for offside as Bayern went in 1-0 up at the break, but the Germany winger struck two minutes into the second half.

When Lewandowski stumbled with the goal at his mercy, Gnabry fired home.

With an hour gone and his side 2-0 down, Dortmund coach Lucien Favre brought on forwards Marco Reus and Paco Alcacer, who have only just recovered from foot and calf injuries respectively.

Alcacer had his head in his hands after failing to connect with an Achraf Hakimi cross with 20 minutes left as Dortmund’s best chance went begging.

Bayern’s third came as Lewandowski finished another counter-attack by the hosts, just before Hummels’ own goal.

“That was a huge disappointment, a lot of our players didn’t play well. Bayern were better,” admitted Dortmund coach Lucien Favre.

Leipzig go second

Earlier, Timo Werner netted twice as Leipzig went second with a 4-2 win at Hertha Berlin in the capital, where the Berlin Wall fell on November 9, 1989.

To mark the 30th anniversary, a replica of the Wall, which divided Germany’s capital from 1961, separated Hertha and Leipzig before being knocked down prior to kick-off.

Midfielder Maximilian Mittelstaedt gave Hertha a first-half lead which lasted six minutes before Werner converted a penalty.

Marcel Sabitzer added Leipzig’s second on the stroke of half-time before three goals came in the final five minutes.

Kevin Kampl netted Leipzig’s third with a superb left-footed strike before Werner grabbed his second for his 11th league goal in as many games, before Hertha striker Davie Selke scored against his former club.

Striker Rouwen Hennings completed his hat-trick five minutes from time as Fortuna Duesseldorf held Schalke to a 3-3 draw.

The Royal Blues squandered the lead three times as goals by Daniel Caligiuri, Ozan Kabak and Suat Serdar in Gelsenkirchen were cancelled out by Hennings.

Union Berlin are up to 11th after their third straight win as Sebastian Anderson scored twice in a 3-2 victory at Mainz.

Augsburg climbed out of the bottom three with a 1-0 win at bottom club Paderborn thanks to a goal by defender Philipp Max.