Joachim Low felt Germany's first-half display and Patrick Herrmann's debut in Wednesday's 2-1 defeat to United States were causes for optimism.
Despite Germany dominating much of the first half, Jurgen Klinsmann's side went in level at the break as Mix Diskerud cancelled out Mario Gotze's opener a the RheinEnergieStadion in Cologne.
However, the visitors controlled the second half and, as in last week's 4-3 victory over Netherlands, Bobby Wood came off the bench to seal the victory.
Low was pleased with Germany's early momentum and singled out debutant Herrmann for praise.
"With the first half, I'm very, very pleased but - in the second half - our performance dwindled," he explained.
"Patrick Herrmann did very well today, because he was key to the goal.
"You could see that our energy was high in the first 45 minutes. We will need to maintain in the next three days."
Germany face Gibraltar in a Euro 2016 qualifier on Saturday and will be almost guaranteed to get back to winning ways against the minnows.
"The game today was important to get back into our rhythm," added captain Bastian Schweinsteiger.
"Sure, we wanted to win but one must also see where the Americans come from and where we come from in terms of fitness levels.
"I'm sure that we will show a good performance against Gibraltar."
