Douglas-Roberts, who spent his two previous NBA season with the Nets, also dished out four assists and grabbed three steals. Ersan Ilyasova notched a double-double with 22 points and 13 rebounds and Corey Maggette added 20 points for the Bucks, who snapped a three-game skid.
Kris Humphries led the Nets with 22 points and eight rebounds in a reserve role. Jordan Farmar scored 20 and dished out a game-high 10 assists for New Jersey, which has dropped two straight and seven of eight overall.
The Bucks led wire-to-wire en route to their sixth straight win in this series.
Milwaukee shot 62.5 percent in the first quarter and carried a 28-15 lead into the second.
Humphries scored 10 points in the second quarter, including a running jump shot in the final seconds, but Earl Boykins' jumper before the buzzer gave the Bucks a 55-45 lead entering the half.
Milwaukee opened the third quarter on a 12-2 run, capped by Keyon Dooling's three-pointer at 7:27, to take a 20-point lead. The Bucks' advantage quickly reached a game-high 26 with a Douglas-Roberts layup and three-point conversion at the 5:00 mark.
The Bucks took an 88-65 lead into the final stanza and the fourth quarter was all but a formality as the teams traded baskets down the stretch.
Boykins and John Salmons scored 17 and 12 points, respectively, for Milwaukee...The Bucks scored 19 points off 14 Nets turnovers...New Jersey played without guard Devin Harris (bruised right quadriceps)...Nets rookie Derrick Favors scored 12 points and Ben Uzoh and Sasha Vujacic both finished with 11 points in the loss.