Hearts goalkeeper Zdenek Zlamal was struck by a coin thrown from the away end during his side's Scottish Cup clash with Rangers.
The Czech stopper was hit in the chest by the object, which he soon picked up and handed to referee Steven McLean.
It isn't the first time the custodian has been the victim of crowd trouble from the Roseburn Stand at Tynecastle. Last season he was attacked by a Hibs supporter as he went to retrieve the ball behind the goal.
McLean took the coin, believed to be a two-pence piece, from Zlamal and gave it to fourth official Willie Collum with under ten minutes remaining in Hearts' 1-0 triumph.
Hearts have said they'll review CCTV footage in order to try and identify the perpretrator.
Oliver Bozanic netted the only goal of the game as Hearts made it to their fourth successive cup semi-final. They all but ended Rangers' chances of domestic silverware this season in the process.