Hamburg pulled two goals back through Nicolai Mueller but Ousmane Dembele came off the bench to net Dortmund 's fifth late on .
Nicolai Mueller netted their first goal in 717 Bundesliga minutes dating back to 10 September .
Hamburg pulled two goals back through Nicolai Mueller , who netted their first goal in 717 Bundesliga minutes dating back to 10 September , but Ousmane Dembele came off the bench to net Dortmund 's fifth late on .