The Trail Blazers were a point behind heading into the final period, but outscored the Bulls during the last 12 minutes 22-10. Chicago played without Derrick Rose for the second straight game.
Wesley Matthews had 18 points for Portland while hitting four 3-pointers. The Trail Blazers were 11-of-21 from beyond the arc.
Portland is 2-4 on a seven-game road trip that concludes Sunday in Oklahoma City.
Carlos Boozer led Chicago with 22 points and 14 rebounds. The Bulls had won three in a row.
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