Saunders (4-5) surrendered five hits and a walk while striking out five, breaking a personal three-start winless streak.
Yoervis Medina followed with 1 2/3 scoreless relief innings and Tom Wilhemsen corralled his 13th save despite allowing a run in the ninth inning.
The Ibanez blast capped a three-run third-inning for Seattle, which claimed the opener of a three-run set.
Kendrys Morales and Jesus Sucre each added an RBI in the victory.
Chisox starter John Danks (0-1) absorbed the loss. The left-hander, making his third start of the season, was touched for four runs (three earned) on seven hits over six full frames.