Troyes remain winless this season following a last-minute defeat to Brest at Stade Francis-le Ble.
Brest started brightly and deservedly went ahead on 11 minutes when Eden Ben Basat tucked away Benoit Lesoimier's low cross with a deft finish from six yards.
Mounir Obbadi scored his second goal in as many matches to pull Troyes level midway through the second half.
However, Brest regained the lead in the fourth minute of stoppage time, as Geoffrey Dernis unleashed an unstoppable right-footed shot from just inside the penalty area that flew into the top left corner.
