Hamburg eased to a 3-1 success over local rivals Werder Bremen in the 103rd Nordderby at the Weserstadion on Saturday.
The sides shared the spoils over the two derbies last season and goals from Ivo Ilicevic, Michael Gregoritsch and Nicolai Muller gave the visitors maximum points to leave Bremen just above the drop zone.
Ilicevic opened the scoring three minutes in with a stunning effort and Gregoritsch doubled the advantage inside half an hour.
Anthony Ujah gave the home fans hope shortly after the hour, but Muller applied the finishing touch to a counter-attack to ensure Hamburg a first win in Bremen since 2009.
Bremen slip to 15th, thanks partly to Hannover's thumping 4-0 against Ingolstadt.
Marcelo, Leon Andreasen, Kenan Karaman and Uffe Bech were on target at the HDI Arena in the hosts' biggest win of the season, while leaders Bayern were 2-0 victors over Hertha Berlin, who slip to fifth.
Goals late in the first half from Thomas Muller and Kingsley Coman moved Bayern 11 points ahead of Borussia Dortmund, who take on Stuttgart on Sunday.
Fabian Johnson haunted his former employers as Borussia Monchengladbach claimed a point in a thrilling 3-3 draw against Hoffenheim at the Rhein-Neckar Arena.
Johnson's fifth-minute opener was cancelled out by goals from Steven Zuber, Eugen Polanski and Nadiem Amiri only for Josip Drmic to score prior to the hour before Johnson levelled three minutes from time.
The other game of the day came at the Coface Arena as first-half goals from Yoshinori Muto and Yunus Mallu gave Mainz a 2-1 win over 10-man Eintracht Frankurt – Haris Seferovic grabbing a consolation after Alexander Meier's dismissal prior to the break.
