"This was a step in the right direction, but we want to get to something bigger, but it was kind of a statement win for us," Durant said.
Kobe Bryant scored 31 points, Pau Gasol added 26 and Andrew Bynum had 12 points and 13 rebounds for the Lakers, who led by five early in the fourth and by one with 3:10 to go, only to see the Thunder close on a 16-2 run.
"We're just playing horrible defense right now. We're just making too many mistakes," Bryant said. "The mistakes that we're making are correctable and a good practice session will correct that."
The Lakers did play better than in their previous four losses by cutting down turnovers. They had just two through the first three quarters, and nine in the fourth.
"The fourth-quarter defense was the best as we could possibly play against one of the best teams in basketball," Oklahoma City coach Scott Brooks said. "Anytime you can beat the Lakers, it's a good win. They're one of the best teams and they haven't won a lot of games lately, but they're going to be right there."
The teams exchanged leads throughout the fourth, with Bryant scoring seven in a row to give the Lakers their last lead. Durant and Westbrook combined for nine of the Thunder's final 16 points.
In the first half, the Lakers gave up 66 points -- their most in a half this season. After the game, Bryant took refuge in the trainer's room and when he returned to his locker, he was noticeably quiet.
"I didn't want to redecorate the walls in here so I made the effort to just go into the training room and keep to myself," he said.
Bryant's free throw after Thabo Sefolosha was called for a technical pulled the Lakers into their first tie, and Fisher's jumper gave them their first lead of the game, 76-74, midway through the third.
The Thunder answered with eight straight points before the Lakers outscored them 13-6 to take a 90-88 lead into the final 12 minutes.
The Thunder led the entire first half, with their largest lead of 12 coming in the opening quarter. They shot 62 percent from the floor, made 6 of 9 3-point attempts and 14 of 15 free throws.
The Lakers came out lethargic. There were four technicals in the first half, including Bryant and Kendrick Perkins, whose arms got tangled with Bryant's head ending up in Perkins' right armpit.
Bryant got disengaged from Perkins and scored seven of the Lakers' next nine points as part of a 20-11 run that energized them as they ended the half trailing 66-64.
The Thunder improved to 13-4 on the first night of back-to-back games. They'll complete their final one of the regular season on Monday at Sacramento. ... The Lakers have dropped three in a row at home. ... Bill Walton was a pregame visitor to the Lakers' locker room looking for his son, Luke.