كتب : Amro Hassan
Jocelyn Roux scored the only goal of the game on 76 minutes, courtesy of a looping shot which went past Egyptian keeper Essam Al-Hadari.
The defeat leaves Sion in eighth position in the table with 17 points.
Sion have a relegation battle to fight in the Swiss league, where the last team is directly relegated, and the ninth-placed club undergo a play-off against a second division side.