Dortmund started with Erling Haaland on the bench, but Sancho continued his fine streak without the Norwegian, finishing confidently in the 15th minute after good work by Thorgan Hazard in one of few first-half highlights.

The contest was momentarily paused early in the second period to allow for an announcement that urged Dortmund fans to halt offensive chants about Hoffenheim backer Dietmar Hopp.

This came after the German Football Association (DFB) banned Dortmund fans from attending Hoffenheim matches for the next two seasons earlier this month, with similar chanting in December triggering a suspended sentence from 2018.

Freiburg became a more prominent attacking threat once play resumed and were unfortunate to not get an equaliser when Lukasz Piszczek cleared Nils Petersen's header off the line.

Dortmund had to withstand further pressure towards the end, but held firm for a hard-earned win that keeps it third and within four points of leader Bayern Munich.