The Grizzlies acquired Wells from the Blazers on Wednesday for Wesley Person and a conditional 2004 first-round draft pick. Wells, who was stripped of his co-captaincy and benched before the trade, waited just three days to face the team that gave up on him.
Portland led by as many as 15 points and was in front, 70-69, with 11 minutes left. But Memphis scored 22 of the next 29 points, including eight by Wells. Pau Gasol finished the run with a technical free-throw after Blazers Coach Maurice Cheeks was ejected, giving the Grizzlies a 91-77 cushion with 72 seconds remaining.
Wells fittingly capped the scoring, burying a running jumper with 40 seconds left, as Memphis (12-8) continued the best start in franchise history.