The Thunder had plenty of chances to tie or take the lead in the final seconds but needed Westbrook's buzzer-beater from the corner to claim victory.
Westbrook scored a season-high 34 points on 10-of-25 shooting while Kevin Durant added 25 as the Thunder won their sixth consecutive game overall and ninth straight at home to start the season.
Stephen Curry scored 32 for Golden State.
San Antonio's Tim Duncan scored 17 of his 19 points in the first half to set up the Spurs for a 109-91 win at Orlando.
Marco Belinelli also had 19 points for San Antonio, which scored 17 straight points in the second quarter to turn a one-point edge into a 58-40 lead, and was able to rest Duncan for much of the second half.
Both teams were without their starting guards, as Tony Parker and Jameer Nelson were both injured in games on Wednesday.
Arron Afflalo scored 17 points for Orlando, who now heads for a six-game, 12-day road trip.
Miami's LeBron James scored 27 points to once again lead the Heat to a 90-83 win over Toronto.
Dwyane Wade had 22 for the Heat, who have won 13 straight over the Raptors and seven straight in Toronto.
DeMar DeRozan scored 25 points for the Raptors.
Atlanta's Al Horford made the go-ahead shot with 4.2 seconds left to complete the Hawks' rally from a 17-point second-half deficit to an 88-87 win over Dallas.
Jeff Teague scored 25 points for the Hawks, while Horford finished with 17 points and 12 rebounds.
The Mavericks were up 70-55 when point guard Jose Calderon went out late in the third quarter with a sprained ankle, and they lost their way from there. Dallas hit just 38 percent, with Vince Carter missing badly on the final shot of the game.
Houston's Chandler Parsons scored 21 points, making six 3-pointers, as the Rockets beat Brooklyn 114-95, easily winning a fourth-straight game.
The Rockets led by 26 points at halftime and Brooklyn coach Jason Kidd benched all his starters except Brook Lopez for the entire second half.
Houston made 19 3-pointers, led by a perfect 6-of-6 effort from Parsons, who scored all his points in the first three quarters. James Harden scored nine points with seven assists for the Rockets in his return from a foot injury.
Lopez was also back after sitting out the last six games with a sprained ankle. He started in place of Kevin Garnett and scored 16 points in about 21 minutes.
Los Angeles' Jamal Crawford had a season-high 31 points, 11 assists and seven rebounds off the bench to help the Clippers beat Sacramento 104-98 after overtime.
Crawford made two free throws with 21 seconds left in the extra period to cap a 10-0 run. Blake Griffin added 21 points and 12 assists for the Clippers, who played without point guard Chris Paul for the first time this season.
The win moved L.A. coach Doc Rivers within one victory of 600 for his career.
Sacramento, which missed two 3-pointers over the final 70 seconds, lost its third straight this season to its Western Conference foes.
Los Angeles' Wesley Johnson scored 27 points and Jordan Farmar led a fourth-quarter rally as the Lakers overcame a 10-point deficit to beat Detroit 106-102.
New Orleans' Jrue Holiday had 20 points and 13 assists in his first game as a visiting player against his former team, leading the Pelicans to a 121-105 win over Philadelphia.
Denver beat New York 97-95, with Knicks star Carmelo Anthony missing a contested, 14-foot jump shot at the buzzer.
Boston's Jeff Green scored 31 points, the most by Boston player this season, to lead the Celtics past Cleveland 103-86.
Phoenix's Markieff Morris scored 23 points on 8-of-13 shooting off the bench to lead the hot-shooting Suns to a 112-101 win over Utah.
Charlotte's Al Jefferson posted season highs with 23 points and 12 rebounds to guide the Bobcats to a 92-76 win over Milwaukee, which has lost 11 in a row.
