Reserve guard Jeremy Lamb added a career-high 18 points to help the Thunder to their fourth consecutive win and 12th in 13 games.
Neither Westbrook nor Durant played in the fourth quarter as the Thunder maintained double-digit leads throughout the final period.
Mike Conley had 20 points for the Grizzlies and Zach Randolph and reserve Jon Leuer each scored 17.
The Thunder shot 50 percent in the first half with Durant (16) and Westbrook (15) combining for 31 points.
CLIPPERS: Doc Rivers picked up another win in Boston.
The coach who led the Celtics to the 2008 NBA title returned for the first time with the Los Angeles Clippers on Wednesday night and beat Boston 96-88.
Jamal Crawford scored 21 points, hitting a pair of 3-pointers 23 seconds apart to help the Clippers pull away in the final 3 minutes.
“It was just a really nice day,” said Rivers, choking back tears in his postgame news conference. “This is, it’s just such a classy place here. ... They cheer for their teams and they love their athletes. The best decision I ever made was 10 years ago, when I decided to come.”
BOBCATS: With injuries mounting at small forward, Charlotte signed Chris Douglas-Roberts from the D-League’s Texas Legends and waived forward James Southerland.
The Bobcats are dealing with injuries to small forwards Michael Kidd-Gilchrist and Jeffery Taylor.
Douglas-Roberts averaged 18.7 points, 4.3 rebounds and 2.8 assists in 34 minutes in six games for the Legends.
RATINGS BONANZA: The Indiana Pacers’ 90-84 victory over the Miami Heat on Tuesday was the most-watched game ever on the league’s NBA TV outlet.
The network says Wednesday that the telecast averaged 920,000 viewers, topping out at more than 1 million from 10:15 to 10:30 p.m. EST.
The game, the first since Miami’s seven-game victory in last season’s Eastern Conference finals, surpassed 868,000 total viewers that watched a Lakers-Portland game last season.
The previous highest rated game this season came Sunday, when 691,000 watched Kobe Bryant’s return against Toronto.