Toni Kroos admits that Germany remain short of their desired level of form despite Sunday's 2-0 win over Ukraine in their Euro 2016 opener.
Shkodran Mustafi's maiden goal for his country gave the world champions a 1-0 lead in the first half, with substitute Bastian Schweinsteiger making the points safe in second-half stoppage time with his first international goal in almost five years.
Germany struggled to hit a consistent rhythm against Mikhail Fomenko's side, who were denied an equaliser in the first half through two superb Manuel Neuer saves and a timely goal-line clearance from Jerome Boateng.
And Kroos, who was named man of the match for a fine display capped by an assist for Mustafi's header, says they must look to build on their improved second-half performance.
"This is just the beginning," he said. "Winning 2-0 and not conceding is great for self-confidence. We had our impressions throughout this game, we passed well in the spaces.
"The last 15 minutes before half-time were not too strong, so we couldn't have complained had we conceded. But we dominated the game in the second half and I don't remember us conceding any chances.
"We're not at the level that we want to achieve in this tournament but it's quite a nice feeling."
Mustafi impressed at the heart of the defence alongside Boateng, with his first-half header and a superb late interception to stop a Ukraine counter-attack capping a strong all-round display.
Kroos praised the Valencia man for his efforts in the absence of the more established Mats Hummels and Antonio Rudiger - even though he felt his goal was a simple task.
"He just had to head it in, it wasn't difficult!" Kroos joked, before adding: "In all seriousness, he had a good game, he's done everything possible to fight for the squad. He has high quality and he helped us. Big compliments to him."
