Westbrook scored 33 points, including 17 in the third quarter, and the Thunder beat short-handed Portland 106-90 on Friday night.
''He was drinking some of that Space Jam juice in here at halftime,'' Durant said with a laugh. ''But really, we're just playing the way we need to play right now.''
Earlier in the evening, the Thunder clinched their third straight Northwest Division title when Dallas defeated Denver 108-105 in overtime. Oklahoma City also remained a half-game up on San Antonio for the top seed in the Western Conference.
Durant added 16 points for the Thunder, who led by as many as 22 points.
''That wasn't a given,'' Westbrook said about the division title. ''A lot of guys came back better, and we've put in a lot of work to put ourselves in a position to win it again.''
Portland, missing the playoffs for the second straight season, lost its 10th straight, the most since an 11-game skid in the 2005-06 season. The team has lost seven straight at home, the most in franchise history.
The Blazers were led by Will Barton, starting in place of injured shooting guard Wesley Matthews, with 18 points.
Portland was sunk in the third quarter when the team was outscored 26-7 by the Thunder. It was a franchise-worst third period total for the Blazers.
''The third quarter, our offense was ground down,'' coach Terry Stotts said. ''We stopped moving the ball. We didn't create shots and we were loose with the turnovers. It was a bad combination.''
The Thunder were without Kendrick Perkins because of a right hamstring injury he aggravated in a 116-97 victory at Golden State on Thursday night. Hasheem Thabeet started in his place.
Thunder guard Kevin Martin was also sitting out because of back spasms.
J.J. Hickson returned to Portland's starting lineup after he missed a game with a sore lower back. But the Trail Blazers remained without Matthews (right ankle) for the second straight game and Nicolas Batum (right shoulder) for the fifth straight.
Both teams were streaky early. The Blazers opened with a 13-12 lead, but the Thunder went on an 11-2 run to take a 24-15 lead after Westbrook's 3-pointer.
Barton capped an 11-2 Portland run with a layup to move the Blazers within 30-28 early in the second quarter. Then Oklahoma City went on an 11-2 run to go up 41-30.
The Blazers took a 46-44 lead with 3:06 left in the first half after a 16-3 run that Victor Claver capped with a 3-pointer. Damian Lillard, who scored a career-high 38 points Wednesday against the Lakers, was scoreless until a reverse layup with 30.9 seconds to go before halftime.
The Thunder took a 55-54 lead into the break after Thabo Sefolosha's 3-pointer at the buzzer.
Oklahoma City opened the second half with a 9-0 run and went up 72-59 on Westbrook's 17-foot jumper. His 3-pointer gave the Thunder an 81-61 lead going into the final quarter.
''All night we were trying to feed him. He had the hot hand,'' Durant said about Westbrook. ''I think he did a good job of moving the ball. He missed some shots, but the ball movement was pretty good tonight and Rus was the main advocate. He did it all.''
Barton's dunk pulled the Blazers to 97-84 with 4:03 left in the game, prompting Thunder coach Scott Brooks to briefly bring back in Westbrook and Durant, who had been sitting since the end of the third quarter.
It was as close as Portland would get.
''There's a reason they went to the finals last year and are fighting for the No. 1 seed in the west again,'' Barton said. ''They're getting ready for the playoffs, so that's what you expect from them.''
Hickson and LaMarcus Aldridge sat out the fourth for the Blazers.
Portland was coming off a 113-106 loss to the Lakers on Wednesday night. Kobe Bryant had a season-high 47 points, most ever scored by an opposing player in the Rose Garden.
NOTES: Earlier Friday, Durant was fined $25,000 by the NBA for making a ''menacing gesture,'' when he pretended to slice his throat after dunking in the second quarter against the Warriors. ... San Francisco 49ers running back LaMichael James, who played for the Oregon Ducks, was at the game. ... The Thunder have won nine of their last 11 in the race to the playoffs. ... Oklahoma City sweeps the season series against Portland 4-0.