The 20-yr-old Schade got here off the bench and stole a march on Leverkusen goalkeeper Lukas Hradecky at a nook to tap the winner into the internet six minutes from time.
Freiburg coach Christian Streich set free a primal scream at the very last whistle as his group move into the wintry weather spoil in their maximum position inside the membership's records.
"We actually wanted to be 1/3 over the festive duration," aim-scorer Vincenzo Grifo told DAZN.
"When we observe the table over Christmas, it makes for precise studying."
Freiburg took the lead at their Europa Park Stadium in Germany's Black Forest whilst Italy forward Grifo chipped in a first-1/2 penalty.
Leverkusen equalised simply before the spoil while Germany defender Jonathan Tah hooked a bypass to Charles Aranguiz who headed past the Freiburg goalkeeper.
However, with time going for walks out Schade ghosted in front of Hradecky and flicked the ball into the net to the despair of the Leverkusen goalkeeper.
Freiburg's defence has conceded a club-document low of sixteen league dreams within the first 1/2 of the season.
The hosts' defence worked tirelessly to include Leverkusen striker Patrik Schick who scored eight desires in his previous three Bundesliga video games.
Freiburg's win noticed them soar-frog Leverkusen into 0.33 spot, 14 points at the back of Bundesliga leaders Bayern Munich.
