Spectators inside the stadium were left bewildered when both teams immediately headed for the tunnel, despite an agreement that a shootout would settle the match in the event of a draw.
Upon seeing the opposition and match officials walk off the pitch, Chelsea's head of first-team operations, Kevin Campello, was seen locked in a heated touchline argument, shouting to the referee: "It's written in the contract."
Despite fierce protests from the Blues' operational staff, the decision stood firm, and the match was officially brought to an abrupt close without a winner.