Bayern Munich crushed Schalke 4-0 on Saturday to move 15 points clear at the top of the Bundesliga after champions Borussia Dortmund crashed 4-1 against SV Hamburg and Bayer Leverkusen also failed to win.
David Alaba's double and goals from Bastian Schweinsteiger and Mario Gomez kept Munich on course for a 23rd national title long before the end of the season.
Artjoms Rudvens and Son Heung Min struck twice for visiting Hamburg in a turbulent game in which Dortmund forward Robert Lewandowski scored the first goal and was then sent off, and Hamburg's Jeffrey Bruma got his marching orders later.
Munich command the standings with 54 points. Dortmund have 39, remaining second because Leverkusen (38) had to swallow a late 3-3 draw at Borussia Moenchengladbach.
'We are not thinking of the championship. We just want to win every game,' Alaba said. 'It was a lot of fun but the three points were more important.'
Munich coach Jupp Heynckes rested Thomas Mueller and Mario Mandzukic, with Arjen Robben and Gomez starting against Schalke, who have won just once in 10 games and slumped from second to ninth in the process.
Alaba opened the scoring from the penalty spot in the 19th after Marco Hoeger brought down Franck Ribery, and wrapped up matters in the 51st from short range.
In-between Schweinsteiger's curling 25m free-kick went in off the left post. Robben fed Gomez for the fourth in the 63rd minute of one-way traffic.
In Dortmund, Lewandowski netted his 14th goal of the season, capitalising from a misunderstanding between Hamburg defender Heiko Westermann and goalkeeper Rene Adler.
Hamburg levelled a minute later from Rudvens' tap and took the lead in the 26th from Son's curling shot from the edge of the area in off the left post.
Lewandowski was shown a straight red card for a fierce tackle against Per Ciljan Skjelbred in the 31st, and Bruma had to go on the hour for a last-man lunge on Marco Reus.
Hamburg assured themselves of victory two minutes later, Rudvens nodding home a cross at the far right post for his 10th goal of the season. Son completed the upset in the 89th.
'We celebrated it like a championship. No one expected this from us,' Hamburg playmaker Rafael van der Vaart told Sky TV, with Son naming the victory 'something special.'
Dortmund coach Juergen Klopp said: 'These things happen in football. We have to accept it.'
Dortmund must regroup quickly from their third home defeat of the season for of Wednesday's last-16 Champions League game at Shakhtar Donetsk, while Hamburg climbed into fifth place.
Leverkusen dominated in Moenchengladbach before the hosts drew first blood on the stroke of half-time, when Martin Stranzl scored with his left shoulder off a corner.
Sidney Sam levelled seven minutes after the restart from 18m, Luc de Jong restored the hosts' lead in the 59th, Stefan Kiessling with his 100th top flight goal and Andre Schuerrle put Leverkusen 3-2 up, but Patrick Herrmann headed a late equaliser for Moenchengladbach in the 86th.
Fourth-placed Eintracht Frankfurt (37) were held 0-0 by Nuremberg, Stuttgart were humbled 4-1 at home against Werder Bremen for their fifth defeat in a row, bottom club Greuther Fuerth lost 1-0 against Wolfsburg and Hanover beat Hoffenheim 1-0.
Sunday's games are Augsburg v Mainz and Freiburg v Fortuna Dusseldorf.