USA, conversely, went into the match requiring a draw to be guaranteed of progress, although third-placed China PR needed to make up an eight-goal deficit.
Despite that backdrop it was Germany who slowly gained a stranglehold, before eventually storming to an unassailable lead with three quickfire goals either side of half-time.
The opening half-hour gave no indication of the one-sided scoreline that was to follow with both teams sharing possession statistics.
However, the deadlock was broken ten minutes before the interval after a defensive error allowed Lotzen to latch onto a loose ball and bravely loop a header over onrushing goalkeeper Bryane Heaberlin.
USA barely had time to settle following the second half restart before they were three goals down.
Firstly, Lotzen pushed home from close range after Heaberlin failed to hold a Lina Magull effort eight minutes after the break.
Then just two minutes later Leupolz cracked home a fine volley from 15 metres after the United States defence again failed to clear their lines.
USA occasionally looked dangerous at the other end, mostly through striker Maya Hayes, but their attacking threat was largely limited.
Dzsenifer Marozsan came close to laying claim to goal of the tournament, but her long-range high effort from close to halfway narrowly missed the target.