But, as it turned out the home supporters were in fact protesting against Bundesliga fixtures being played on Monday nights.
A freaky video assistant referee (VAR) decision caused mayhem in a Bundesliga game on Monday night when two teams were ordered back on to the pitch at half time because the referee chose to award a penalty after watching a replay on TV.
Following a nervy first half Mainz took the lead in curious circumstances when they were given a penalty by Video Assistant Referee system VAR after the referee had already blown for half-time. After reviewing the incident he then decided that Freiburg had handled the ball in the area at the end of the first-half, meaning Mainz now had a penalty seven minutes into the interval!
Daniel Brosinski tried his luck before half-time and his shot took a deflection off Freiburg defender Marc Oliver Kempf's hand.
Freiburg coach Christian Streich, who was recently sent off for dissent in a league match, was on the sideline smiling and shaking his head in disbelief after being told to get his players back out on the pitch. "That wasn't the case in this scene, we have to accept that with heavy hearts".
The confusion continued after the break, as fans threw toilet rolls onto the pitch in protest against Monday night games, delaying the restart by several minutes.
Mainz climbed to 15th on goal difference above Freiburg who fell to 16th, the relegation playoff spot.
De Blasis eventually added a second goal for the hosts late in the game following a mistake by Freiburg keeper Alexander Schwolow. Wolfsburg is also under threat with four rounds remaining, while survival looks increasingly unlikely for Hamburger SV and Cologne, eight and nine points adrift of safety, respectively.