In addition to Durant's 38, Westbrook poured in 30 points. Reggie Jackson added 14 off the bench.
For the Nuggets, Ty Lawson had a huge night with 29 points and eight assists. J.J. Hickson dominated inside on his way to 19 rebounds and 18 points.
But lack of energy in the fourth quarter and missing 18 free throws overall doomed Denver.
Key Player Grades
Kevin Durant, OKC Thunder, SF
Kevin Durant's shooting percentages are down a bit this season, but it hasn't really mattered because of how often he gets to the free-throw line.
The most free throws per game he's ever averaged for an entire season was 10.2 in 2009-10. After attempting 16 free throws Monday night, his average for 2013-14 is 12.8.
There were several possessions in this game when Durant almost seemed more intent on getting to the line then he did on getting by his defender or making a shot. It's not a bad strategy when you get the calls and shoot 88.3 percent from there.
The free throws carried Durant for much of the game. He struggled from the field, going 11-of-27 on the night. But then, when OKC needed a bucket most, Durant hit a huge three with 1:26 left in the fourth quarter to break a 105-105 tie.
In addition to his 38 points, Durant tallied eight rebounds and six assists.
Russell Westbrook, OKC Thunder, PG
For most of Monday night's game, Russell Westbrook's play caused me to shake my head and wonder if he cares one bit about getting good possessions.
So much of his game is just plain reckless and does little to get anyone else involved.
And then the fourth quarter happened.
Suddenly, Westbrook seemed much more under control. The pull-ups he took were open and in the flow of the offense. He even looked for the team's best player on a few big possessions.
Then, with under 30 seconds left in the game, he killed J.J. Hickson with a crossover in the lane and finished a shot at the rim when it mattered most.
But perhaps Westbrook's biggest contribution came on the boards. He finished with a team-high 12 rebounds to go along with his 30 points on 10-of-25 shooting.
Serge Ibaka, OKC Thunder, PF
At first glance, Serge Ibaka's line of six points and seven rebounds might not look terribly impressive. But five of those boards came on the offensive end, including one which set up Durant's huge fourth-quarter three.
He was also solid as usual in protecting the rim; he finished with three blocks.
Thabo Sefolosha, OKC Thunder, SG
The development of Thabo Sefolosha's three-point shooting is an underrated story for the Oklahoma City Thunder. He's no longer a one-dimensional defensive specialist.
He's struggled so far this season, but from 2011-12 to 2012-13 he shot 42.2 percent from downtown. He went 2-of-3 from three on Monday night.
Kendrick Perkins, OKC Thunder, C
As long as he continues to not only play, but start Kendrick Perkins, I can't help but question Scott Brooks' coaching. He offers next to nothing on either end of the floor.
Tonight, he went 1-of-4 from the field for two points.
Reggie Jackson, OKC Thunder, PG/SG
It's unfair for people to expect Reggie Jackson to fill the sixth-man role as effectively as James Harden once did for OKC. But they do need some scoring behind Durant and Westbrook, and Jackson was solid enough on Monday night.
He was just 4-of-11 from the field, but he hit all four of his free-throw attempts and knocked down two three-pointers.
And much like Westbrook, Jackson is a great rebounder for a guard. He finished with seven against the Nuggets.
Bench, OKC Thunder
Lack of depth could become a very real issue for the Thunder as they pursue title contention.
Jackson was solid Monday night, and Jeremy Lamb's performance (eight points on 3-of-5 shooting) was encouraging.
But one of the things that made OKC so good the year they went to the finals was the explosiveness of James Harden.
Again, I don't expect anyone on this roster to reach that level, but they will need more consistency from the bench. The other two bench players who scored against the Nuggets were Nick Collison and Derek Fisher. They combined for nine points on 3-of-8 shooting.
Ty Lawson, Denver Nuggets, PG
Ty Lawson was fantastic for three quarters on Monday night, but he pretty much disappeared in the fourth. He was 9-of-17 from the floor overall but just 2-of-4 during the final frame.
He was slicing his way through OKC's defense at will and knocking down mid-range jumpers for most of the game, but for some reason he became significantly less aggressive down the stretch.
Denver's offense became very stagnant as a result of Lawson taking his foot off the gas.
Wilson Chandler, Denver Nuggets, SF
Denver's offense has looked much better overall since Wilson Chandler returned from injury, but he struggled mightily on Monday night against the Thunder.
After hitting his first two jump shots, Chandler hit just one of his next 10 attempts from the field. He was also part of the team's woes at the free-throw line, where he shot 1-of-3.
It wasn't all bad for Chandler, though. His defense is a big part of his game and was part of why Durant shot so poorly from the field.
Kenneth Faried, Denver Nuggets, PF
Kenneth Faried wasn't quite as prominent on Monday night as he has been for the Nuggets recently. In 25 minutes, he finished with just six boards and five points.
Nights like this one are evidence that Faried needs to add another weapon to his arsenal. He'll always bring the effort on the boards, but when the ball isn't bouncing his way, he needs to have a reliable mid-range jump shot.
J.J. Hickson, Denver Nuggets, C
Unfortunately, J.J. Hickson's night may be best remembered for the nasty crossover with which Westbrook victimized him.
That breakdown aside, Hickson was fantastic Monday night.
It's becoming more evident with each game that Faried might not be the only "Manimal" on the Denver Nuggets. Hickson has ferociously attacked the glass all season on both ends of the floor.
On Monday night, Hickson grabbed 19 rebounds, six of which were offensive. At times, all Serge Ibaka could do was grab Denver's big man, hoping the refs wouldn't see it.
A lot of the offensive boards led to putback attempts. He finished with 18 points.
Randy Foye, Denver Nuggets, SG
On Monday night, Randy Foye did exactly what he was brought to Denver to do. He doesn't need to score a ton of points for the threat of his shooting to be important.
Such was the case against the Thunder. Foye scored 11 points and hit 2-of-5 from downtown. His presence on the floor forced the Thunder to pay attention to the perimeter, leaving more space for Hickson to operate inside.
Evan Fournier, Denver Nuggets, SG
The sixth-man role has been kind of like a game of musical chairs for the Nuggets this season. Tonight, Evan Fournier got the most burn off the bench. He was excellent in 17 minutes.
He scored 12 points on 4-of-7 shooting, and I couldn't help but wonder, "What happens when Danilo Gallinari comes back?"
All of a sudden, Denver might have a ton of depth on the wing with those two and Wilson Chandler.
Bench, Denver Nuggets
Bench players not named Fournier scored 30 points on 11-of-21 shooting. Jordan Hamilton, Timofey Mozgov, Darrell Arthur and Fournier all played over 15 minutes, and all were effective.
Nate Robinson may have been a nice contributor off the bench as well, but he was unfortunately sidelined with an injury:
He looked as though he was on his way to his best game of the season, scoring 10 points on 3-of-5 shooting. But he didn't see the floor in the second half and finished with just under nine minutes.
The Nuggets will get the Chicago Bulls at home on Thursday at 10:30 p.m. ET.
It looks like a good opportunity for a bounce-back game for Denver. The Bulls are solid, but with the slow-paced offense they bring, they might struggle to keep up with the Nuggets.
It seems like Denver coach Brian Shaw has finally relented on wanting to slow things down and sees that the players he has are great for running.
The Thunder have a huge matchup at home against the Los Angeles Clippers on Thursday at 8 p.m. ET.
Both teams are legitimate threats to win the Western Conference, and neither has displayed much of an ability to play defense. It should certainly be a high-scoring affair.
The Thunder will have to be better defensively against the offensive powerhouse from L.A. than they were against Denver tonight if they want to win this one.
For 140-character pearls of wisdom from Bleacher Report's Andy Bailey, follow him on Twitter: @AndrewDBailey.