Dortmund demolishes Freiburg
Marco Reus scored twice before half-time, with Fallou Diagne sent off for the visitors for giving away the penalty the led to the hosts' second.
Dortmund, who lost Marcel Schmelzer for three weeks due to a thigh strain he picked up in training on Friday, started with Erik Durm as left full-back, but an otherwise full-strength side.
It took them a while to assert this strength, however, against the only side to have taken points off Bayern this season.
In spite of their possession, Dortmund were unable to break down a well-drilled Freiburg defense, trying with the strength of Lewandowski, the pace of Pierre-Emerick Aubameyang and the intelligence of Henrikh Mkhitaryan and Reus.
Something had to give eventually and it was Reus who gave the hosts a deserved lead 10 minutes before half time.
Sven Bender's distance shot was only parried by Oliver Baumann, who then blocked Lewandowski's effort, but was powerless to deny Reus at the third attempt.
Dortmund were gifted the chance to double their lead just before the interval when Diagne brought Lewandowski down in the area, earning a red card as he was the last defender.
Reus stepped up and dispatched the ball in off the inside of the post.
Lewandowski made it three in the 58th minute with Reus this time the provider as the Freiburg defense slowly started to crumble.
The Polish striker showed all of his talents to beat two defenders and then lift the ball over Baumann to seal victory for the Westphalians.
There was more to come from Dortmund and from Lewandowski as he scored for the 10th time against Freiburg, and his fourth brace, stroking Jonas Hofmann's pass over the line with Baumann nowhere to be seen.
Lewandowski's compatriot Blaszczykowski got in on the act with 10 minutes remaining, pouncing to intercept a weak back pass and dribble round Baumann before sending the ball in from a tight angle.