Jerome Boateng has apologised to Bayern Munich fans for Saturday's shock 2-1 defeat at relegation-threatened Freiburg which means Pep Guardiola's side have lost five of their last six games.

"We simply have to play better football than today and for that we need to apologise to our fans," fumed Boateng.

The Germany defender was the laughing stock of social media earlier this month when he was left sprawling on the turf by Lionel Messi's quick footwork as the Barcelona star scored in Bayern's 3-0 Champions League, semifinal, first-leg defeat at the Camp Nou.

Having been knocked out of Europe's premier club competition 5-3 on aggregate, despite a 3-2 home win against Barca on Tuesday, Bayern's bad week continued as Freiburg's super-sub striker Nils Petersen scored against his former club.

The Freiburg result followed Bayern's cup defeat at Dortmund and league losses against Leverkusen and Augsburg, plus the away defeat at Barca in Bayern's nightmare three-week period since winning their 25th German league title.

"Freiburg wanted to win it more and showed more fight," admitted Bayern coach Pep Guardiola, whose side will be presented with the Bundesliga trophy at home to Mainz next Saturday.

"It's not been easy for us since winning the title.

"We have one last game – then we can go on holiday and look at the future."

Bayern took the lead at Freiburg when Bastian Schweinsteiger marked his 500th Bundesliga appearance by hammering home a cross with 11 minutes gone.

But to the delight of the Freiburg crowd, the hosts drew level when midfielder Admir Mehmedi hit the bottom left-hand corner on 33 minutes.

Freiburg were unlucky not to be awarded a penalty after Bayern defender Rafinha fouled Mehmedi in the area early in the second half, while Schweinsteiger hit the crossbar with a free-kick 20 from time.

But Petersen hit Freiburg's winner just three minutes after coming off the bench to seal their first win over his former employers in 19 years.

He converted Karim Guede's pin-point cross, which just eluded Boateng's out-stretched boot, on 89 minutes.

The result lifted Freiburg out of the relegation places to 14th.

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