The Minnesota Timberwolves, boosted by a brilliant fourth quarter from diminutive guard JJ Barea, beat Oklahoma City 99-93 to end the Thunder's 12-games winning streak.
The NBA-leading Thunder battled back after an early 14-points deficit to move within a point at 76-75 early in the fourth before Barea took over.
Barea scored 10 points in a 12-2 run that restored Minnesota's double-digit lead at 88-77 and then helped the T-Wolves hold off the Thunder the rest of the way.
The loss dropped Oklahoma, last year's losing NBA Finalists, to 21-5 while Minnesota improved to 13-11, seven games behind the Thunder in the Western Conference's Northwest Division.
Kevin Love led Minnesota with 28 points and 11 rebounds, and center Nikola Pekovic had 24 points and 10 boards, while Barea came off the bench to score 18 points.
Three-times scoring champion Kevin Durant paced the Thunder with 33 points, and Russell Westbrook added 30, but Oklahoma City's reserves contributed seven points in all.