Gabon blew their chance to become the first country to qualify for the Africa Cup of Nations quarter-finals as they were beaten 1-0 by Group A rivals Congo.
After a quiet start, Gabon were the first side to carve out a decent chance when Malick Evouna was played in by Levy Madinda on 20 minutes, but the young striker could only fire his shot straight into the arms of Christoffer Mafoumbi.
Two minutes later, Pierre-Emerick Aubameyang flashed an effort over the bar, before Evouna saw another chance come his way when he collected Madinda's pass in the Congo box, but before he could get his shot away Boris Moubhibo made a crucial intervention.
On the stroke of half time Madinda should have put his side ahead when he skipped around the challenge of Moubhio, but with the goal at his mercy the Celta de Vigo midfielder somehow sliced the ball wide of goal.
Congo then went ahead within two minutes of the restart as Prince Oniangue fired home from close range following a scramble after Gabon failed to deal with a corner.
Arnold Bouka Moutou's volley from the edge of the box nearly doubled Congo's lead, but was beaten away by Didier Ovono.
Gabon could have been level when Aubameyang picked out Evouna in the box, but he dragged his shot wide of the post.
With Congo tiring, Gabon dominated possession in the final minutes, but failed to test Mafoumbi leaving Congo to claim their first win in 41 years in the Cup of Nations.
