The Thunder won their 12th straight home game and denied Los Angeles the chance to head into the midseason break with back-to-back statement wins on the road.
The Lakers had won at defending NBA champion Dallas a night earlier and were trying to follow it by knocking off the other half of last year's West finals.
"It's a regular game for us," Durant said, downplaying any significance of a midseason victory.
"Of course, we respect those guys and they're champions and they've won multiple rings, but it's another game for us. You're just trying to get better every single day."
Oklahoma City and Miami both have NBA-leading 27-7 records at the break. The Lakers are 20-14 and sitting in fifth place in the West.
"It's cool that we're winning games but we can't be complacent," Durant said.
"We've been on a good roll lately. We've got to just keep working hard. It's not over yet. We're glad we're going into the break with some wins but I think it's important for us to come out of the break with some energy and some momentum."
The Thunder pulled away in the second half to win their second in a row against the Lakers, who won eight of the teams' previous nine regular-season meetings and knocked Oklahoma City out of the 2010 playoffs in the first round.
"They did a great job. They took advantage of opportunities when they presented themselves, jumped out to a good cushion and we could never get the game back in balance," Bryant said.
The Lakers, once able to use their size advantage against Oklahoma City, struggled to get those same inside baskets against the remade Thunder interior of NBA blocks leader Serge Ibaka and Kendrick Perkins.
Center Andrew Bynum started out 2-for-12 before finally hitting three in a row midway through the fourth quarter. His two-handed slam got the Lakers within 81-74 with 7 minutes remaining, only for Oklahoma City to come right back by scoring the next seven points on a three-point play by Westbrook and dunks by Harden and Perkins.
Los Angeles didn't get any closer than nine after that.
"Going into this game, we really wanted to keep them out of the paint, keep them away from the basket and rebound the shot," Thunder coach Scott Brooks said. "Just give them one shot -- one and done, and get out and run."
Harden scored 16, and Ibaka added 11 points and 13 rebounds for Oklahoma City, which limited L.A. to 39 percent shooting while making 47 percent of its own shots.
"We have to work too hard to get points going up against defenses that are set and double-teams all the time," Bryant said. "Having a little bit more movement, it'll free Andrew up, free Pau up, free myself up to where I don't have to work against two guys all the time."
Bryant said he didn't have any expectations for where the Lakers would be at the midpoint of their first season under Mike Brown and considered himself "neutral" about their play so far.
He had made waves recently by criticizing management about leaving Gasol to wonder whether he'd be traded, but general manager Mitch Kupchak didn't back down.
"Just trucking along," Bryant said. "As you can see, we still have things we have to figure out about how we're going to play and how we're going to execute.
"It's going to take time, especially in this type of season when we don't have any practice time."
The Thunder emerged ahead 46-43 after a closely contested first half, with Westbrook connecting on a 3-pointer from the left wing with 0.8 seconds left and Durant stealing Bynum's inbounds pass along the left baseline before hitting a jumper before the buzzer.
Bynum and Metta World Peace, his intended target, walked off the court discussing what went wrong.
The Lakers would never lead again.
Durant converted a three-point play and Daequan Cook hit a 3-pointer during a burst of eight straight points for Oklahoma City midway through the third quarter, and the lead stretched to 71-58 when Cook followed Harden's slam by hitting a right wing jumper with 1:43 left in the period.
"We didn't close the half off well at all, and then the third quarter they were more playing their game and we were making it a little easy for them by not moving the ball, by the ball getting stuck on one side of the floor and settling for jumpers," Gasol said.
"They just came out and ran. That's what they do."
After looking back at the video, Brown said he thought a foul by Dallas' Brendan Haywood on Gasol in the final minute Wednesday should have been a flagrant foul. "I'm sure the league has seen it and I'm sure that they'll take whatever action they think is necessary for it. That definitely was not just a normal foul or a regular foul," Brown said. ... Durant was a late addition to the 3-point contest at the All-Star Game, giving him a chance at redemption after last year's last-place effort in which he scored only six of a possible 30 points. "His last year's performance was pathetic. ... Right now, he needs coaching," Brooks said. "We need to bring back the H-O-R-S-E contest so he can bring something home." Durant won the H-O-R-S-E contest in 2009 and 2010. ... Perkins is just two technical fouls away from a one-game suspension, with 11 through 34 games. "It's going to be very difficult for Perk to not engage in any physical play on the court that referees deem that's a little excessive but he has to," Brooks said.