Bayern’s ninth successive Bundesliga title will have to wait as they fall to a 2-1 loss against Mainz.
First-half goals from Burkardt and Quaison came either side of Lewandowski squandering a glorious opportunity for the visitors.
Jonathan Burkardt stunned the visitors after three minutes, turning at the edge of the box to score as Mainz enjoyed a powerful start, twice hitting the woodwork in the first 18 minutes with the Bavarian defence in complete disarray.
The in-form hosts, unbeaten now in their last seven league games, got a deserved second goal in the 37th when Quaison drilled in a header from a free kick.
In the second half, Svensson’s men sat deep while appearing relatively untroubled before Lewandowski grabbed a late consolation goal for the Bavarians in additional time.
The Bavarians took control of the game after the break but created far too few chances until top striker Robert Lewandowski scored his 36th goal of the campaign, after returning from four weeks out with injury, with the final kick of the game.
Bayern, who have three games left, are on 71 points, 10 clear of Leipzig, who play VfB Stuttgart on Sunday.
Flick’s side could be Bundesliga champions by their next game, in which they host Borussia Monchengladbach, if second-placed RB Leipzig fall to defeat against Stuttgart tomorrow.
Mainz, who are now seven unbeaten, jump up to 12th, five points clear of the relegation zone with the added bonus of a game in hand. They next face Hertha Berlin a week on Monday.