Leon Balogun was sent off in Mainz 05’s 0-0 draw with Hamburg at the Volksparkstadion.
The Nigeria international was dismissed after a second caution - his second red card in his professional career - as Sandro Schwarz's men settled for a share of the spoil in Saturday's league tie.
The former Werder Bremen centre-back was first cautioned the 34th minute before being sent out by referee Markus Schmidt after fouling Luca Waldschmidt inside the penalty area in the 61st minute.
Consequently, the Red Shorts were awarded a penalty but Filip Kostic could not get his effort past debutant Florian Muller who parried his shot onto the crossbar.
Both teams - currently battling relegation - pushed to break the deadlock but Muller’s brilliance between the sticks stood out for visitors as Hamburg saw their early goal ruled out by VAR for offside.
Nigeria’s Anthony Ujah was introduced for Yoshinori Muto with two minutes remaining – his fifth substitute appearance since his move from Liaoning Hongyun in January.
Balogun will serve a one-game ban and miss the O-Fives next league outing against Schalke 04 at the Opel Arena.
Mainz 05 remain in the relegation playoff place with 25 points from 25 games.