Grasshoppers have taken over as leaders of Switzerland's premier football division by one point after beating lowly Yverdon 1-0.
Rainer Bieli scored the winning goal in the 60th minute.
Lugano hold on to their second spot, alongside Basel, despite losing their match 1-0 to strugglers Neuchatel Xamax.
In what was perhaps the most exciting of Sunday's matches, Neuchatel won with a late goal by Henri Camara.
St Gallen are in fourth position overall with 30 points. They were 2-1 beaten by Sion.
FC Zurich outclassed Lucerne, who are also lagging in the bottom half of the table, and won the match 2-0.
swissinfo with agencies