Watch: After VAR debacle, Freiburg goalkeeper gifts Mainz second goal with horrible blunder
The Bundesliga clash was already eventful enough with ongoing protests aimed towards the league's hierarchy for playing the match on a Monday, and a VAR incident which plunged the match into disarray.
But the battle at the bottom took another downward turn for visitors Freiburg - and Schwolow in particular.
Pablo de Blasis had already beaten the German goalkeeper with a penalty in the seventh minute of first-half injury-time, following a lengthy VAR debate, before the Argentine was gifted his second goal in the 78th minute.
Schwolow lazily attempted to pass the ball out to a team-mate despite being chased down by Robin Quaison. The Swedish forward intercepted the loose pass and squared to De Blasis to apply a simple finish (which he did his best to mess up, admittedly).
And we all thought Joe Hart had a difficult Monday night...
Mainz's 2-0 win was their first home victory since January 20, and means they've now switched league positions with Freiburg. Die Breisgauer have dropped into the relegation play-off spot - 16th - due to their inferior goal difference.