Jurgen Klopp tasted defeat for the first time as Germany manager as his side lost 1-0 to Greece in Augsburg on Sunday, with Dimitrios Kourbelis scoring the only goal.
In his first game on home soil, Klopp's side offered little in attack and lacked the energy they had displayed on the former Liverpool coach's debut in a 1-1 away draw with the Netherlands on Thursday.
The Germans had struggled to find a way through the Greek defense for the opening hour before the visitors broke through on the counter, with Kourbelis scoring in the 74th minute.
It was Greece's first ever win against Germany.
"Personally, I'm completely unbothered by it. I've lost far more matches in my life than I would have liked," Klopp told ARD.
"But as long as you draw the right conclusions, a loss is ultimately just a piece of information -- no different from a win.
"We absolutely need these kinds of matches -- they are exactly the games we wanted to have."
Germany captain Joshua Kimmich added: "He's been very clear about what he wants -- as players, we need to implement it."
- 'Very hyped' -
Several regulars missed out with Klopp trying to get a better idea of the talent at his disposal, but the defeat illustrated the scale of his task in reviving the flagging giants.
The 59-year-old took over Germany in July after the four-time World Cup winners were eliminated at the last-32 stage of the global showpiece in North America, their third consecutive early exit from the tournament.
"I think the important thing is that we stand together and that won't change," said Germany center-back Jonathan Tah.
"Of course, with the enthusiasm surrounding the new coach, things can get very hyped up from the outside, but ultimately, it comes down to what we do on the pitch and how we perform."
Klopp had included 16 uncapped players in his 44-man squad as he warned that he would be using the competition to have a look at the players at his disposal.
Among the five alterations to his starting XI was Hoffenheim forward Bambase Conte, a shock call-up after playing just four top-flight matches.
Conte looked sharp and shot just wide with two minutes gone.
Barcelona forward Karim Adeyemi had the best chance of the opening half when he stormed past the Greek defense on the counter, but sprayed his shot just over the crossbar.
Conte was again dangerous after the break, forcing a low fingertip save from Greek goalkeeper Konstantinos Tzolakis.
With Germany dominating possession but offering little in attack, the visitors grew bolder and more incisive on the counter and should have taken the lead when Fotis Ioannidis blasted wide of the goal with just Alexander Nuebel to beat.
Greece broke through moments later, however, when Kourbelis's low shot took a wicked deflection off Joshua Kimmich and rolled into the bottom left corner.
Greece then held firm for a breakthrough win over Germany, after seven defeats and three draws dating back to 1960.
