Asthe elevatordoorsclosed, Itried to correctmymistake and doublepressed the button for the fourthfloor, hopingit woulderasetheselections and prevent an unnecessarystop.
However, the double substitution had its desired effect as both men pressed forward, pressurising South Korea's defence for the first time in the match.
Arsenal refused to be discouraged by the setback and pressed forward with urgency, but another moment of defensive frailty almost saw Chelsea double their advantage on the hour.