Dach deflected in a shot from the right point by Louis Crevier for his second goal of the season.
Ryan Greene and Teuvo Teravainen also scored, and Spencer Knight made 31 saves for the Blackhawks (9-5-4), who are 4-0-1 in their past five games.
Joseph Woll made 29 saves in his season debut, and Nicholas Robertson and Morgan Rielly scored for the Maple Leafs (8-9-2), who have lost five in a row (0-4-1).
Woll missed Toronto’s first 18 games for personal reasons.
Greene gave the Blackhawks a 1-0 lead at 11:05 of the first period. Defenseman Artyom Levshunov circled the offensive zone and skated into the right face-off circle before making a cross-ice pass to Greene, who scored from the bottom of the left circle.
Robertson tied it 1-1 at 19:12. John Tavares circled the net, and his attempt was stopped by Knight, but the puck slid off Knight’s stick and Robertson scored from in front.
Rielly gave the Maple Leafs a 2-1 lead at 9:37 of the second period. He retrieved the puck in front of the net after a shot by Oliver Ekman-Larsson was deflected and knocked it in high to Knight’s glove side.
Teravainen tied it at 5:12 of the third period. Frank Nazar made a backhand pass from the right boards to Teravainen, who moved through the slot and scored on backhand-to-forehand move.