Okur also pulled down 14 rebounds, while Devin Brown added 13 points on 4-of-4 shooting including three three-pointers off the bench for the Jazz, who have won three of their last four games.
Jamaal Magliore scored 14 points and grabbed 16 rebounds, and Michael Redd scored 19 for the Bucks, who have lost two of their last three games.
"We executed down the stretch and we played good defense," said Williams. "Those are some of the things that we have struggled with in the past. We would play good ball for 40 minutes and then crumble down the stretch. Tonight we did a good job of staying with it."
Redd's two free throws pulled Milwaukee within 83-78 with 1:29 remaining, but the Bucks couldn't get any closer.