Borussia Dortmund were held at Hannover thanks to a late equaliser from former Manchester United striker Mame Biram Diouf.
Jurgen Klopp's Polish contingent opened the scoring for Dortmund after 26 minutes when Lukas Piszczek squared to Lewandowski, who made no mistake with a simple finish.
Dortmund were forced to deal with a number of injuries to key players throughout the match, with Jakub Blaszczykowski, Mats Hummels and Sven Bender all forced off with various knocks.
Hannover pressed in the second half, desperate to maintain their unbeaten home record, and came close on a number of occasions.
Didier Ya Konan had a shot cleared off the line before Mario Eggiman had a goal controversially ruled out for a foul in the build-up.
Ten minutes from time Diouf inexplicably missed an open goal from six yards out when he failed to connect properly when he passed an incisive cross into the hands of a relieved Roman Weidenfeller.
Diouf made up for his mistake with a neat turn and finish from close range five minutes later after Ya Konan deflected a free kick into the forward's path.
A battling point for Hannover extends their unbeaten home record to 23 matches, while Dortmund are left trailing league leaders Bayern Munich by nine points after just seven matches.