Allie Quigley and Cheyenne Parker scored 15 points apiece and Kahleah Copper 11 for Chicago (4-1).
Arike Ogunbowale had 26 points and five assists for Dallas (2-3). Kayla Thornton scored 13 points and Allisha Gray added 12.
Ogunbawale made a wide open layup to trim Dallas' deficit to 80-79 with 13.5 seconds left. After the Sky called timeout and the ball was moved to midcourt where, immediately after the inbound pass, the Wings trapped Vandersloot and forced a jumper ball. Dallas gained possession but, after a timeout, Parker had the last of her foul steals, poking the ball away from Dallas rookie Satou Sabally.
Vandersloot made two free throws with 0.1 seconds remaining.