Viciedo, who had given the White Sox a 1-0 lead with a run-scoring single in the first inning, made it 3-0 in third with a two-run shot off Ryan Dempster (0-2). The next batter, Pierzynski, also went deep, and the White Sox went on to clinch their three-game series with the crosstown rival Cubs at Wrigley Field.
Adam Dunn socked a solo homer and drew four walks for the White Sox, who won their third straight overall.
John Danks (3-4) tossed 6 1/3 shutout innings to earn the victory, surrendering only three hits while walking one and striking out four.
Dempster remained winless in seven starts for the Cubs despite being one of the league's leaders in earned run average. The right-hander allowed four runs on seven hits in a six-inning effort.