© AFPAlphonso Davies celebrates his equaliser for Bayern Munich
Bayern Munich battled back to claim a 3-3 draw against Arminia Bielefeld in a storm-laden Bundesliga thriller.
Greeted by heavy snow on their return from Club World Cup glory, Bayern were caught cold by their relegation-threatened opponents as debutant Michel Vlap and Amos Pieper stunningly gave Arminia a 2-0 half-time lead.
Robert Lewandowski scored his 25th Bundesliga goal of the season in sumptuous fashion three minutes into the second period, although substitute Christian Gebauer swiftly replied for Uwe Neuhaus' men.
Corentin Tolisso and Alphonso Davies continued the flow of easy-on-the-eye goals, but Bayern could not find a winner.
Manuel Prietl reacted quickest when Cedric Brunner's ninth-minute long throw was partially cleared and Vlap - a loan signing from Anderlecht - controlled his drilled pass superbly before emphatically smashing beyond Manuel Neuer.
Bayern had the chance to regroup shortly afterwards as snow was swept off the pitch lines and the officials reverted to orange match balls.
Tolisso almost capitalised when Leroy Sane swung a cross through the blizzard to cause confusion in the Arminia box.
But Bayern were left with a snow-covered mountain to climb when Pieper was left unchallenged to head home Vlap's left-wing corner for his first ever Bundesliga goal.
The groundstaff hurried along a half-time thaw, allowing Bayern to make their class tell early in the second half.
Stefan Ortega Moreno got down sharply to thwart Sane before Lewandowski's exquisite chest control and volleyed finish from David Alaba's chip left the goalkeeper with no chance.
Remarkably, Arminia restored their two-goal advantage within a minute - Andreas Voglsammer tearing past Bouna Sarr to deliver a pinpoint low cross that gave Gebauer - another man opening his account for the club - a simple finish.
Sane and Tolisso combined again for the latter to head home before the hour, while Kingsley Coman was providing a similar threat from the other wing as he had a venomous drive tipped over.
In the 70th minute Sane got to the byline and his right-footed cross was cleared only as far as Davies, who fizzed a magnificent half-volley into the bottom left corner.
Back came Bielefeld and a marginal offside against Fabian Klos denied Sergio Cordova a fourth, before they held out for the point their endeavours deserved.