The game was Bucks coach Scott Skiles first visit to the United Center since he was fired by the Bulls last season. The teams will meet again in Chicago on Tuesday night in the regular-season opener.
Derrick Rose, the former Memphis star drafted first overall by the Bulls, left in the first quarter because of a strained right hip flexor, but is expected to play Tuesday night in the regular-season opener. He was hurt driving for a layup.
"It's not a big deal at all," said Rose, who left the court for the balance of the first half. "I could have played in the second half, but they told me to sit down."
"(Rose) wanted to go back in," Del Negro said. "But there's no sense taking a risk there. We got him some rest. He'll be fine."
Chicago's Ben Gordon (jammed left big toe), guard Larry Hughes (dislocated right shoulder) and forward Luol Deng (sore right toe) missed the game. "It has been hard to evaluate our rotation because of all the injuries," Del Negro said.
Milwaukee center Andrew Bogut sat out because of a sprained left ankle.
The Bulls (4-4) led 54-35 at halftime and 78-66 entering the final quarter, but the Bucks (1-1) used a 20-4 run to take an 86-82 lead.
Chicago tied it at 95 tie on Joakim Noah's rebound tip-in.