(CNN) -- It was Bayern Munich's first league defeat this season -- and the German club's first in 54 Bundesliga games. It even came against one of the team's Bavarian rivals.
But coach Pep Guardiola is already looking ahead to a bigger prize.
With the domestic title wrapped up in record time, the Spaniard rang the changes for Saturday's match against Augsburg as he introduced three teenage debutants.
It backfired spectacularly, as an error by young defender Mitchell Weiser handed striker Sascha Molders a first-half goal that ultimately settled the match for the eighth-placed home side -- beaten 2-0 by Bayern in the German Cup in December.
But for Guardiola, the main thing was his squad escaped unscathed ahead of Wednesday's Champions League quarterfinal second leg against Manchester United, which he described as "a matter of life or death."
The defending champions will be without suspended midfielders Javi Martinez and Bastian Schweinsteiger following the midweek 1-1 draw at Old Trafford.
"We fought hard and tried different approaches. You can't always win. A defeat was on the cards sooner or later," Guardiola said.
"We accept that and we need to prepare as soon as possible for the game against Manchester United. We didn't lose because of the younger players. Hojbjerg and Weiser were the best players on the pitch.
"They've trained with us a lot, they know how we play and also know what I want. Hats off to the three of them. We're in a final on Wednesday. It's a matter of life and death."
Goalkeeper Manuel Neuer emphasized the importance of the upcoming European match. His team's only defeat this campaign came in the group stage against Manchester City, with qualification already assured.
"The main thing for us was that nobody got injured today. That's the crucial point," he said.
"It's all about Wednesday and the match against Manchester United. Nothing else matters."
Bayern's defeat meant second-placed Borussia Dortmund closed the gap to 20 points with a 2-1 win at home to Wolfsburg.
Poland striker Robert Lewandowski, who missed Dortmund's 3-0 Champions League defeat at Real Madrid in midweek due to suspension, celebrated his return with the equalizing goal after Ivica Olic's opener. Marco Reus netted a 77th-minute winner.
Third-placed Schalke could only draw 1-1 at Werder Bremen, while Borussia Monchengladbach moved above Bayer Leverkusen into fourth on goal difference with a 2-0 win at second-bottom Nuremberg.