Chivas USA (4-7-5) won on the road for only the second time this season and got its second consecutive shutout. San Jose (4-7-4) lost its third consecutive game by a 1-0 margin and has now gone 315 minutes since scoring its last goal.
The Earthquakes failed to clear Mauro Rosales' cross into the box after two botched headers. Torres was waiting for the ball at the far post and slid a roller to the left corner of the net to give Chivas USA the lead in the 53rd minute.
The Earthquakes have been playing without leading scorer Chris Wondolowski, a member of the U.S. World Cup team, who just missed scoring a dramatic late goal against Belgium on Tuesday in Brazil.