Brandon Jennings, Samuel Dalembert and Mike Dunleavy each scored 13 points for the Bucks (2-1), who shot 41.9 percent from the field. Rookie John Henson exited with a left knee injury and did not return.
The Bucks pulled to 94-91 after a 14-4 run capped by Beno Udrih's two free throws with 3:02 left.
Robinson responded with a jumper, and Hamilton and Carlos Boozer each hit two free throws to put the game away.
Milwaukee pulled within six in the third quarter, but the Bulls answered with a 13-3 run for a 79-63 lead.
The Bulls last trailed 30-29 late in the first quarter, but Robinson hit a 35-footer before the buzzer to give Chicago the lead for good.
Nazr Mohammed scored eight points during the Bulls' 17-2 run to open the second quarter, extending Chicago's lead to 49-32.
Blake Griffin and Chris Paul are progressing in their respective recoveries after they suffered playoff-ending injuries, coach Doc Rivers said Thursday.
Although there was no blockbuster deal to be made with his many picks, Danny Ainge said he was really excited about the players that the Celtics added.
Have the Thunder closed the gap on the Warriors as the best team in the West? Kevin Pelton looks at OKC's upside after the Serge Ibaka trade.