Viciedo's one-out blast deep into the left-field seats off Kameron Loe (1-1) handed the Chisox the rubber match of their three-game set against Seattle.
Closer Addison Reed (1-0) was credited with the win after working through a touchy top of the 10th, during which he struck out Michael Morse with runners on first and second to end the inning.
Kendrys Morales went 3-for-4 with a bases-empty blast and Morse supplied a two-run shot for Mariners.
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