Oliech played the full 90 for the Burgundy side as they maintained their push for a promotion place with a nervy win.
The game burst into life in the second period, with the first half cagey at best and producing little in the way of attacking opportunities, in the process frustrating the home crowd.
Last 20 minutes
It however exploded in the last 20 minutes, with Auxerre taking the lead through Terrence Makengo on 70 minutes.
However, the visitors replied eight minutes later through Romain Rocchi, but Auxerre again hit back with five minutes to go through Georges Paul Ntep to ensure victory.
The win means Auxerre are eighth in the standings, five points behind leaders Monaco.