Celtic suffered an embarrassing Scottish League Cup third round exit, losing 1-0 at home to second-tier Morton after extra time on Tuesday.
Dougie Imrie scored a penalty for the Scottish Championship strugglers in the 97th minute after Efe Ambrose was penalised for handball.
Celtic manager Neil Lennon made five changes for the tie and, while it was one-way traffic for the Scottish champions and Champions League participants, they could not find a way through.
The Scottish League Cup is the only domestic trophy Lennon has yet to win.
Morton have won just one of their six second division games this season and are second-bottom of the table.