Borussia Dortmund coach Jurgen Klopp found it hard to accept the goal which prevented his side from moving 12 points clear at the top of the Bundesliga.
Mainz striker Petar Sliskovic scored an 89th-minute equaliser at the Westfalen Stadion to make the score 1-1, despite the fact that Dortmund defender Neven Subotic had been lying on the floor for the best part of 10 seconds after being winded by a Mainz shot.
Mainz continued to play and did not kick the ball out to allow Subotic to receive treatment, and Sliskovic stole into the gap vacated by Subotic in the centre of the Dortmund defence to earn his side a point, much to Klopp's annoyance.
"You saw him lying there,'' said Klopp in an interview with Sky television together with his Mainz counterpart Thomas Tuchel after the match. "I would have been ashamed in such a situation and I would not be happy to get a point for it. The fact is, it could have been seen.''
Tuchel denied that his team had seen Subotic on the ground, but decided to carry on nonetheless.
"It is not on to allege that my players had seen the man on the floor and intentionally carried on,'' he said. "Your team also had the chance to put the ball out of play.''
But Klopp said it was not so much the players' behaviour which angered him, but rather the reaction of Tuchel and the Mainz bench to the goal.
"You all saw Subotic lying there,'' he accused. "The whole bench saw it, but you did not care less. What annoyed me the most is how you all celebrated it.''
Nevertheless, Klopp admitted his side's failure to win the game "was totally down to us'' for failing to take their earlier chances, including a missed penalty from Neven Subotic.
"In that respect, the result is fair enough,'' he added.