Jennings drained four key foul shots in the final 30 seconds, helping to turn back a late Trail Blazers charge and enable Milwaukee to finish a four-game road trip with a 3-1 mark.
He finished with 30 points, eight assists and three steals. Ersan Ilyasova added 27 points and 14 boards, while Monta Ellis helped out with 13 points, five rebounds, five assists and five steals for the Bucks.
Portland, meanwhile, dropped a season-worst fifth straight.
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