Portland's Damian Lillard has scored a career-high 51 points to lead the Trail Blazers to a stunningly dominant 137-105 victory over NBA leaders the Golden State Warriors.
The Warriors on Friday lost for only the fifth time this season, and looked well below their best in their first game back from the All-Star break.
They were among the three divisional leaders to lose on the day: Oklahoma City were beaten at home by Indiana and Toronto were defeated by an undermanned Chicago.
In another key result, Miami won at Atlanta to leave the teams in a virtual tie atop the Southeast Division.
Portland's CJ McCollum added 21 points for the in-form Blazers, who have won nine of 10 to improve to 28-27, the first time they've been over a .500 winning percentage since they were 3-2 on November 4.
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Stephen Curry led the Warriors with 31 points and five assists but it was not nearly enough to prevent an end to the team's 11-game winning streak.
The Blazers used a stifling defence throughout the game, but especially in the third quarter when they forced the defending champions into 13 turnovers.
Indiana's Monta Ellis scored 27 points to help the Pacers win 101-98 at Oklahoma City.
Chicago shook off the absence of Jimmy Butler, Nikola Mirotic and Joakim Noah, and a five-game losing skid, to beat Toronto 116-106.
Miami also won in the absence of key players, taking a 115-111 victory at Atlanta.
Utah's Derrick Favors had 23 points and 10 rebounds to help the Jazz beat Boston 111-93.
San Antonio beat the Los Angeles Lakers 119-113 in the final matchup between Kobe Bryant and longtime Western Conference adversary Tim Duncan.
Bryant, who is retiring at season's end, had 25 points in 29 minutes for the Lakers.
Duncan finished with 12 points and 13 rebounds, and Tony Parker scored 25 points to help San Antonio complete a four-game season sweep. The Spurs moved within three games of defending champion Golden State in the race for the league's best record.
Orlando's Victor Oladipo had 17 points and a career-high 14 rebounds and hit the three-pointer that put the Magic ahead for good in overtime against Dallas on the way to a 110-104 win.
Washington led throughout and eased up in beating Detroit 98-86, led by John Wall's 22 points.
Charlotte's Kemba Walker scored 25 points as the Hornets edged Milwaukee 98-95 despite leaving out newly acquired guard Courtney Lee due to lack of training time with the team.
Memphis' Mike Conley had 25 points as the Grizzlies defeated Minnesota 109-104.
Sacramento's DeMarcus Cousins had 37 points and 20 rebounds in a performance that led the Kings past Denver 116-110.
Houston's James Harden had 27 points and 10 rebounds to lead the Rockets to a 116-100 win against Phoenix, which has lost 25 of 27.
Brooklyn's Brook Lopez scored 33 points as the Nets beat New York 109-98 to hand the Knicks their seventh straight loss.
New Orleans' Anthony Davis scored 18 of his 34 points in the first quarter to set up a 121-114 win against Philadelphia.
