Serge Gnabry said Germany's under-21s had secured a "milestone" win as his goal in Finland put them five points clear of Austria at the top of their European Championship qualifying group.
Germany won 1-0 at the OmaSP Stadion in Seinajoki on Tuesday as Austria drew 1-1 with Russia in qualifying group seven with two games remaining.
Former Arsenal winger Gnabry, now at Werder Bremen, continued his fine form after scoring six times at the Olympics when he struck shortly before half-time.
The 21-year-old told the official German FA website: "Today was a milestone. Those three points were very, very important."
Germany play their two final games against third-placed Russia and second-placed Austria in October, and could secure their place at next summer's finals with a win against Russia.
"We are in very good position for the next match and are looking forward to it," Gnabry said.