The visiting Raptors pulled level with Milwaukee at 2-2 in the best-of-seven Eastern Conference first-round series, which continues Monday in Toronto.
The series winner faces a second-round matchup against either defending NBA champion the Cleveland Cavaliers or the Indiana Pacers.
Elsewhere, the Atlanta Hawks led wire-to-wire en route to a dominating 116-98 victory over Washington, cutting the Wizards lead in the playoff series to 2-1.
DeRozan had a slam dunk and two key assists in a 12-2 run late in the third quarter that put the Raptors ahead 64-55 and they never trailed again.
"We were aggressive on both ends," DeRozan said. "We got stops when we needed to, were aggressive when we needed to be and we kept it up for 48 minutes."
After missing all eight shots of his shots from the field and managing only eight points in a 104-77 game-three loss, DeRozan hit 12-of-22 from the floor and 9-of-9 from the free throw line.
"It won't happen twice," DeRozan said of going scoreless from the floor. "It will never happen twice."
Kyle Lowry added 18 points while Serge Ibaka had 10 points and eight rebounds for the Raptors, who shot only 41 percent from the floor but kept the Bucks to just 37 percent.
Tony Snell led Milwaukee with 19 points.
In Atlanta, forward Paul Millsap registered his second consecutive double-double by finishing with 29 points and 14 rebounds as the Hawks clawed their way back into the Eastern Conference series.
Millsap was 12 of 20 from the floor and had five assists. The only blemish on his night was missing 4-of-9 free throws. Millsap had 19 double-doubles during the regular season.
Game four of the series is Monday in Atlanta.
Atlanta also got 27 points and nine assists from Dennis Schroder. Rookie Taurean Prince scored 16 points.
John Wall tallied 29 points, seven assists and four rebounds for the Wizards. Wall scored 32 points in each of the first two games.
Brandon Jennings came off the bench to score 13 points. Bradley Beal was six of 20 and scored 12 points and Bojan Bogdanovic added 11 points for the Wizards.
© Agence France-Presse
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