Lucerne edged to the top of the early
Sion pulled level through Hungarian defender Vilmos Vanczak's 64th-minute effort as Lucerne moved a point above Thun having played a game more, while Sion climbed to third, a point above Servette who have a game in hand.
Reigning champions Basel lost for the first time this season as they slipped to a 2-1 defeat by FC Zurich at St Jakob-Park.
David Abraham gave the hosts the lead on the half-hour mark, but Zurich staged a stunning comeback with three minutes left as Mathieu Beda equalised and substitute Amine Chermiti scored a 90th-minute clincher.
The result left the sides locked together on six points after five games each, with Zurich in fifth having the better goal difference.
