Kilmarnock's Scottish Premier League clash with Hibernian was abandoned 10 minutes into the second half due to safety reasons.
A supporter collapsed with the game tied at 1-1 and is said to have required CPR.
"Both teams have now left the park, our thoughts are with the supporter at this time," read a statement on Kilmarnock's Twitter page.
The club later confirmed that referee Kevin Clancy had chosen to abandon the game.
Hibernian took the lead in the 20th minute through Alex Harris, but Killie hit back before the break courtesy of Kris Boyd.
An ambulance drove pitch side to take the unwell supporter to hospital, but his current condition is unknown.
