Monreal gave Arsenal the lead, only for Clucas to peg them back within a minute
A minute of madness saw Arsenal take the lead, before being pegged back immediately by Swansea during Tuesday night's Premier League game.
After half an hour in which Swansea were the better side, Arsenal took the lead against the run of play.
Mesut Ozil was awarded far too much space 25 yards out and he floated a ball to the back post where Nacho Monreal prodded home to continue his fine goalscoring form of late.
However, Arsenal's celebrations were cut short as Swansea levelled within a minute.
Ozil was caught in possession in his own half and Alfie Mawson took control of the ball.
The defender looked up and slipped Sam Clucas in behind, with the midfielder slotting past Petr Cech with the minimum of fuss.
Check out the goals for yourself below:
Monreal 1-0: