Williams finished with 12 points, 11 rebounds and a career-high 13 assists to become the third player in franchise history with a triple-double.
Williams was coming off a season-high 21 points Wednesday in an 80-63 victory over the Sparks to help end the Sky’s six-game losing streak.
Nneka Ogwumike scored 14 points and Dearica Hamby had 12 points and 12 rebounds for the Sparks (7-9). Azura Stevens added 13 points, Karlie Samuelson had 11 and rookie Zia Cooke scored 10.
Sparks starter Jordin Canada suffered a shoulder injury in the first half and did not return.
The Sparks, who fell to 2-5 on the road, shot 42% from the field and 31% from beyond the three-point arc.
Kahleah Copper added 17 points and Marina Mabrey scored 13 of her 15 in the first half for Chicago (7-9).
Elizabeth Williams scored 12 points for the Sky.
Chicago made 65% of its shot attempts in the first half and scored the first 11 points after halftime to extend its lead to 54-38.
The Sky’s lead was trimmed to 62-58 before they scored the next seven points to take control.
Smith made a three-pointer with 3:32 left in the fourth quarter for an 82-65 lead.