AC Milan's Kevin-Prince Boateng walked-off the pitch in protest after being subjected to racist chants during a friendly match against fourth-tier side Pro Patria.
The match was abandoned when the midfielder, who was in possession, picked up the ball in the 26th minute and kicked it towards the stand behind him.
The former Tottenham and Portsmouth player then stormed off the pitch.
A player from Pro Patria attempted to talk to the Ghanaian as he departed but Boateng left the field and was quickly followed by his teammates and officials.
The midfielder applauded other sections of the crowd, who then appeared to angrily react towards the section where the chants had come from.
Boateng later tweeted:
AC Milan's official website was running a text commentary of the game and posted the following message on the 26th minute:
AC Milan's Urby Emanuelson tweeted:
Milan coach Massimiliano Allegri said he was "saddened" by the events.
Manchester City captain Vincent Kompany, Manchester United's Rio Ferdinand and Stoke City's Michael Owen all tweeted in support of Boateng.
The match was goalless at the time, with Muntari having had a goal disallowed for offside.