Russell Westbrook scored 37 points, leading six Oklahoma City players in double figures on Tuesday in a 122-105 NBA victory over the Los Angeles Lakers.
Westbrook added 10 rebounds and Kevin Durant scored 26 points and grabbed nine rebounds for the Thunder, whose two turnovers equalled an NBA record for fewest in a game held by the 2006 Milwaukee Bucks and 2009 Cleveland Cavaliers.
Kobe Bryant scored 30 points for the Lakers, but was hampered by a right elbow injury suffered in the first quarter.
Steve Nash equalled his season-best with 20 points, but it wasn't enough to stop the Lakers from again falling below .500.
The Lakers, trying to get themselves in playoff position in the Western Conference, had taken their record to 30-30 with a victory over Atlanta on Sunday.
But they got off to a slow start against the Thunder, who raced to a 7-0 lead, held a 37-28 edge after the first quarter and never trailed.
Durant was key to the Thunder's red-hot start, scoring 20 of his 26 points in the first half.
"Obviously our slow start didn't help any," said Lakers coach Mike D'Antoni, who said his team was also hurt by 16 turnovers along with misses from the field and foul line.
"We battled through some injuries, battled through some foul trouble," D'Antoni said, noting that Dwight Howard's sore shoulder was aggravated early. "We had to play a little bit better to beat a good team."
Bryant said the Lakers failed to deliver defensively.
"We gave up 20 fast-break points. We gave up a lot of points in the paint. We let them attack our rim all night long. We weren't sound defensively," he said.
Despite their deficiencies, the Lakers managed to close the deficit to five points in the fourth quarter, as Nash's three-pointer with 6:14 to play made it 105-110.
But the Lakers were unable to score again. Oklahoma City scored the last 12 points of the contest, a run that included a three-pointer from Serge Ibaka and a two-handed dunk by Westbrook.
The Lakers had little time to regroup before a game in New Orleans on Wednesday.
D'Antoni said the task facing his team was simple: "They've got to play like it's a playoff game."