The White Sox refused to let Brady House's eighth-inning home run be the final word, answering immediately with a walk-off sacrifice fly from Antonacci to defeat Washington 5-4 at Rate Field.
Erick Fedde anchored Chicago's effort with 5.2 innings, allowing just one earned run despite four walks. The right-hander carried a 3.42 ERA and scattered three hits while working around constant traffic on the basepaths.
House's 374-foot homer to right-center tied the game 4-4 in the eighth, his second RBI of the night after driving in Millas with a fielder's choice in the fifth. But Chicago responded in the bottom half when Vargas scored on Antonacci's sacrifice fly to left, giving the White Sox their decisive margin.
Washington starter Fedde's counterpart struggled with control, walking four batters in two innings of work while allowing three earned runs. Jordan Leasure earned the win for Chicago, allowing House's homer but nothing else in his one inning of work.
Chicago snapped a losing streak to improve to 10-15. Washington fell to 11-15 with their second straight loss.