Bayern's youths see off Kovac's Frankfurt as Cologne are relegated
With all eyes on Tuesday's Champions League clash with Real Madrid, Bayern rested several key players, giving first-team debuts to the 20-year-old Dorsch, as well as teenagers Meritan Shabani and Franck Evina.
Dorsch gave Bayern the lead from close range just before half-time, and Sandro Wagner doubled the advantage in the second half. Sebastien Haller grabbed a goal back for Frankfurt, before Rafinha and Niklas Sule wrapped up victory for the hosts.
Bayern will face Frankfurt and Kovac again in next month's German Cup final in Berlin.
Nils Petersen scored a goal in each half to give Freiburg a comfortable lead, before a dramatic late comeback from Cologne.
Leonardo Bittencourt netted two goals in five minutes to give the visitors hope, but a late strike from Lucas Hoeler sealed Cologne's fate.
Fellow strugglers Hamburg, meanwhile, fuelled hopes of a miraculous escape with a 3-1 win in Wolfsburg.
Bobby Wood fired Hamburg ahead from the penalty spot on 43 minutes, ending his 247-day goal drought.
Lewis Holtby doubled the lead moments later, nodding Tatsuya Ito's cross into the far corner. Josip Brekalo pulled a goal back for Wolfsburg 12 minutes from time, but Luca Waldschmidt secured victory in stoppage time for Hamburg.
Hamburg's third win in four games puts them just two points adrift of safety as they bid to avoid a first relegation in their history.
Elsewhere, Schalke drew 1-1 with Borussia Moenchengladbach, while Hertha Berlin rescued a point against Augsburg.