Two moments of misfortune cost Celtic dearly as Arsenal won 2-nil at Parkhead to leave the Scots chances of joining the Champions League group stages hanging by a thread.
Arsenal captain Cesc Fabregas' free-kick took a wild deflection off William Gallas to give the Gunners a half-time lead before Gary Caldwell knocked Gael Clichy's cross past his own keeper to secure an impressive away victory.
Arsene Wegner's side are now overwhelming favourites as they take a healthy lead to London for the second leg of this play-off tie at the Emirates Stadium in two weeks time as Tony Mowbray's side went down to their second successive home European defeat.