Joe Ledley’s second-half header gave Celtic a deserved Europa League point against Rennes at the Route de Lorient but once again Neil Lennon was left to count the cost of a costly defensive mistake.
On the half-hour mark, with the game evenly-matched, a long punt by home keeper Benoit Costil was making its way harmlessly through to Fraser Forster but there appeared to be no communication between him and Cha Du-ri, who helped it on then watched in horror as the ball slipped past the Hoops keeper and in to the net.
That the South Korean was playing in midfield and only back as last man as a safeguard as Glenn Loovens and Charlie Mulgrew were still up the other end following a set-piece, made it harder to stomach for the Celtic boss.
It looked like another disappointing European night was on the cards for the Parkhead men but they mounted a spirited fightback and in the 70th minute Ledley flicked a Mulgrew free-kick over Costil to give the visitors a draw although they still remain bottom of Group I on goal difference.