The Memphis Grizzlies stunned the Oklahoma City Thunder, despite Kevin Durant scoring 37 points for the visitors.
A dominant spell at the start of the second half set the Grizzlies up for the win, with Courtney Lee adding a season-high 24 points.
The injury-hit Los Angeles Lakers continued to struggle, losing to the Cleveland Cavaliers.
Luol Deng, who joined the Cavaliers as part of a trade last week, scored 27 to help the visitors open up a lead during the third quarter.
The Lakers, who will now spend the next two weeks away from home while the Staples Center hosts the Grammy Awards, had just nine players available for the game.
The New York Knicks' recent unbeaten run came to an end with a defeat to the Charlotte Bobcats.
Al Jefferson scored a season-high 35 points, while Kemba Walker dominated the fourth quarter to ensure a win for the home side.
The Knicks, who had been on a five-game winning streak, benched guard JR Smith for the second time in a week, while Carmelo Anthony was the only player to make an impact with 20 points and six rebounds.
The Indiana Pacers secured a comfortable win over the Sacramento Kings at Bankers Life Fieldhouse.
Paul George led the way, scoring 31 points, including four three-pointers, to lead the Pacers to the 30th victory of the season.
Results in full: New York Knicks 98-108 Charlotte Bobcats, Sacramento Kings 92-116 Indiana Pacers, Oklahoma City Thunder 87-90 Memphis Grizzlies, Cleveland Cavaliers 120-118 Los Angeles Lakers
