Germany won their opening game of Euro 2016 thanks to goals by Shkodran Mustafi and Bastian Schweinsteiger in an entertaining 2-0 win over Ukraine on Sunday, but the world champions will be worried by some lapses at the back.
Mustafi headed in his first international goal after 19 minutes and substitute Schweinsteiger netted on the break in injury time.
But Ukraine could easily have levelled at 1-0 against a slightly makeshift Germany defence, giving other sides hope that Joachim Loew's side can be conquered, especially if they again fail to fully kill off a game.
The Group C encounter was end-to-end at times and played in a carnival atmosphere, despite news of trouble between fans in Lille city centre before kick-off.
Germany are level at the top on three points with Poland, who beat Northern Ireland 1-0 in their tournament opener on Sunday.
"I'm very happy for Bastian Schweinsteiger after all this work he has done in the last few weeks and months, he scores the decisive second goal and that helps him and the team," Loew told a press conference.
"It was quite an intensive, physical game. We ran a lot in the first half."
Goalkeeper Manuel Neuer was handed the captain's armband, with the injury-hit Schweinsteiger not match fit enough to start having played very little football since March.
As expected, Mats Hummels was also on the bench as he recovers from injury with Mustafi coming in at centre back and Benedikt Hoewedes remaining at right back.
Mario Goetze, who got the nod upfront ahead of Mario Gomez, made a good early run with his brightly coloured boots to set up Julian Draxler but he scuffed his effort wide.
Immediately at the other end, Mustafi made a mistake and Ukraine winger Yevhen Konoplyanka forced Neuer into a smart save.
Heavy rain before kick-off at the space-aged stadium in Lille meant the pitch threatened to cut up slightly but generally offered a slick passing surface for some flowing German moves, with personnel in midfield interchanging impressively.
But the threat from crosses was always there and when dead ball specialist Toni Kroos swung in a superb free-kick midway through the first half, Mustafi was there to perfectly power a header into the top corner of the net.
Mustafi was outjumped soon afterwards though in his own box and Yevhen Khacheridi produced a header which Neuer had to palm over the bar, as Germany's defence continued to look shaky.
It was Ukraine keeper Andriy Pyatov who was next called upon to make a good save from Sami Khedira after a delightful through ball from Kroos.
The pace of the game would not let up and Jerome Boateng had to block and then clear off his own line after Konoplyanka passed up a superb chance following a clever cross from fellow Ukraine winger Andriy Yarmolenko.
Moments later the ball was in the back of the Germany net but a correct offside flag ruled it out, despite the protests of the yellow-clad Ukraine fans behind the goal.
The second half was a less frenetic affair although Kroos clipped the top of the bar. Ukraine ran out of steam as an attacking force but almost equalized late on after an awful misunderstanding between Mustafi and Neuer.
Then Schweinsteiger popped up to superbly convert Mesut Ozil's cross just minutes after coming on to send the noisy German fans away happy.
"Germany are a machine, they are a team full of great players. We didn’t know exactly who would play but a machine is a machine," Ukraine coach Mykhailo Fomenko said.
Germany next play Poland at the Stade de France on Thursday when Ukraine face the Northern Irish in Lyon.