COLOGNE: Luca Waldschmidt scored one day after his 21st birthday for Hamburger SV to clinch Bundesliga survival with a late 2-1 win over Wolfsburg on the final day of the season on Saturday.
Filip Kostic, who dragged Hamburg level, crossed for Waldschmidt to head the home side's winner with two minutes remaining, leaving Wolfsburg to fight relegation.
"We were dead and we fought back," said Hamburg coach Markus Gisdol, who was soaked in beer from the celebrations.
Wolfsburg, which had taken the lead through Robin Knoche's unstoppable header midway through the first half, faces a two-leg playoff against the third-place finisher in the second division - all but certain to be Eintracht Braunschweig - to determine which side plays in the Bundesliga next season.
Hamburg goalkeeper Christian Mathenia secured his side's place in the top flight with a brilliant save from Maximilian Arnold in injury time.
Hamburg, which survived relegation playoffs in 2014 and 2015, remains the only side to have played every season in the Bundesliga since the league formed in 1963.
Elsewhere, Pierre-Emerick Aubameyang's late penalty in a 4-3 win over Werder Bremen fired Borussia Dortmund directly into the Champions League, leaving Hoffenheim, which could only draw at home with Augsburg 0-0, to enter the qualifiers.
Bayern Munich, which wrapped up the title with three games to spare, and second-placed Leipzig had already qualified for the Champions League.
Cologne and Hertha Berlin qualified for the Europa League.
"It's one of the nicest days in my life. Like Christmas, birthday and New Year's Eve all rolled together," Cologne midfielder Matthias Lehmann said.
BORUSSIA DORTMUND 4, WERDER BREMEN 3
Marc Bartra, who was wounded in the bomb attack on Dortmund's team bus last month, made his return against Bremen.
"It was unbelievably emotional to the end," said Dortmund coach Thomas Tuchel, whose side remained unbeaten at home over two seasons.
Marco Reus equalized for the home side at 1-1 and 3-3, and Aubameyang secured Dortmund's third-place with another penalty in the 89th minute.
It took the Gabon striker's season tally to a league-best 31 goals.
"It's a huge achievement, from the whole team," Aubameyang said.
Dortmund next turns attention to the German Cup final against Eintracht Frankfurt.
COLOGNE 2, MAINZ 0
Yuya Osako set up Jonas Hector before the break and sealed Cologne's win late to secure fifth place and European football next season.
BAYERN MUNICH 4, FREIBURG 1
Bayern kicked off its title celebrations by bidding farewell to retiring World Cup winners Xabi Alonso and Philipp Lahm before kickoff.
Arjen Robben opened the scoring early, but there were to be no further goals until Arturo Vidal scored in the final 20 minutes. Nils Petersen pulled one back against his former side, before Franck Ribery and Joshua Kimmich completed the scoring in injury time.
"My first beer-shower was very cold but it was fun," Bayern coach Carlo Ancelotti said of the post-game celebrations.
OTHER GAMES
Kai Havertz scored twice as Bayer Leverkusen won 6-2 at Hertha Berlin, which nevertheless finished sixth and qualified for the Europa League.
Leipzig drew at Eintracht Frankfurt 2-2, Schalke drew at relegated Ingolstadt 1-1, and Borussia Moenchengladbach was held by relegated Darmstadt to 2-2.