The Loyal's first meeting with Oakland was decided by one player's first goal in a San Diego uniform.
Miguel Ibarra fired a rocket to break a scoreless tie in the 72nd minute Tuesday night, the lone goal in San Diego's win over the Roots.
Former Torero Miguel Berry delivered a back heel pass to set up Ibarra to turn and fire on goal. Berry, a Poway High School grad, has three goals and one assist in seven matches this season with his hometown team.
Landon Donovan's club has now gone seven matches without a loss, highlighted by four consecutive wins.
Austin Guerrero turned away a pair of shots to post a clean sheet, the team's first of the season.
The Loyal continue a five-match homestand Saturday at 4:00 p.m. against Sacramento.