Bayern Munich striker Robert Lewandowski scored the vital goal in a tense 1-0 victory over his former club Borussia Dortmund in the Bundesliga on Saturday.
The win left champions Bayern 10 points clear at the top of the table despite a string of high-profile absentees.
Polish forward Lewandowski, who joined the Bavarian giants this season, shrugged off a hostile welcome on his league return to the Signal Iduna Park, heading in the winner on the rebound in the Bundesliga's showpiece game.
Victory lifted Bayern to 67 points while Dortmund suffered a setback in their hunt for a European spot, remaining 10th on 33 points following their first defeat in eight league games.
Missing injured Arjen Robben, Franck Ribery and David Alaba among others, Bayern lacked their usual punching power but they made up defensively by completely shutting out the hosts.
"Obviously we fielded a different team, when you are missing players like David, Arjen and Franck," captain Philipp Lahm told reporters.
"It was tight until the end but we defended very well although we did not have a lot of possession.
"It is always great to win in Dortmund against a team that has been our biggest rivals in the last years."
The 80,667 sell-out crowd had to wait 16 minutes for the first shot on goal in a finely-balanced and physical first half.
With a new-look midfield of Lahm, Xabi Alonso and Bastian Schweinsteiger, Bayern gradually found space to go forward while efficiently shutting down space for the hosts.
Dortmund had the edge in the second half but, apart from a fine Marco Reus free kick in the 88th that Manuel Neuer did well to save, they struggled to break past a tight Bayern back line on the way to their second home league defeat of the year.
Earlier, Borussia Moenchengladbach scored three times in 10 minutes to come from a goal down and demolish hosts Hoffenheim 4-1 to tighten their hold on a Champions League spot.
Second-placed VfL Wolfsburg struggled initially against VfB Stuttgart but two goals from Swiss international Ricardo Rodriguez and another from Andre Schuerrle, his first for the club, earned a 3-1 win.
Bayer Leverkusen also took a big step towards a top-four finish, crushing relegation-threatened Hamburg SV 4-0 with two goals from Gonzalo Castro to stay in fourth on 48 points, nine ahead of Schalke 05, in fifth, who are in action at Augsburg on Sunday.
Former European champions Hamburg, who were defeated in interim coach Peter Knaebel's debut game, are in 16th place, the relegation playoff spot.