The Timberwolves owned a four-point halftime lead before Boston dominated the final two quarters thanks to 52 percent shooting.
Minnesota had been trying for its third straight win during a stretch in which the Timberwolves will play six of seven on the road.
Kevin Love scored 19 points and had 13 rebounds for the Timberwolves. Love was coming off his worst game of the season, one in which he managed only six points in a win over Philadelphia.
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