Because Borussia Dortmund also won, 2-1 in Stuttgart, Bayern remained 20 points ahead with seven games to play and mathematically can still lose the title.
But if Bayern wins next week in Frankfurt, it will still become the earliest champion in Bundesliga history.
With a Champions League quarterfinal against Juventus looming on Tuesday, Bayern coach Jupp Heynckes rested several players. But his team quickly seized control against a hapless Hamburg on a damp and cool evening.
”Juventus is going to be a very different story, they are a different caliber,” Bayern midfielder Bastian Schweinsteiger said.
It was the biggest win in the Bundesliga in 13 years and Bayern’s biggest since 8-1 against Schalke in the 1987-88 season. Hamburg had lost its last two games in Munich by 5-0 and 6-0, respectively, and the latest trip quickly turned into another nightmare.
Xherdan Shaquiri scored unchallenged in the fifth minute and Bayern got rolling.
Shaqiri provided the cross for Bastian Schweinsteiger’s goal in the 19th, Pizarro pounced on a corner from Arjen Robben in the 30th and then set up Robben in the 33rd, before scoring again in the 45th.
Robben and Pizarro picked up where they left off after the break.
In the 53rd, Robben set up Pizarro, who slotted home with his heel. One minute later, Pizarro returned the favor, robbing Jeffrey Bruma and setting up Robben for an easy goal.
Pizarro notched his fourth in the 68th. Normally Bayern’s third-choice striker after Mario Mandzukic and Mario Gomez, Pizarro had not scored this season until Saturday.
Bruma headed in a corner in the 75th but substitute Franck Ribery replied for Bayern one minute later.
Hamburg’s second also came after a corner from Rafael van der Vaart, with Heiko Westermann heading into the net.
”I am ashamed for what happened tonight,” Westermann said.