Westbrook finished with 23 points, 18 rebounds and 13 assists for the Thunder, who were down 18 in the opening minutes before outscoring the Heat 39-12 in the fourth.
The 27-point margin was the third-worst for any quarter in Heat history, and the worst ever in a game at Miami.
Josh Richardson scored 18 points and Hassan Whiteside added 16 for the Heat, whose playoff seed won't be decided until the season-finales Wednesday. Justise Winslow and Tyler Johnson each scored 12 for Miami, and James Johnson added 11.
The Cavaliers pulled within a half-game of Philadelphia for the No. 3 spot in the Eastern Conference, bouncing back from their loss to the 76ers on Friday and winning for the sixth time in seven games.
They reached 50 wins for the fourth time in four seasons since James returned from Miami and the 11th time in franchise history.
J.R. Smith and Jordan Clarkson added 16 points apiece for the Cavaliers, who made 19 3-pointers and won for the ninth straight time at Madison Square Garden.
Michael Beasley scored 20 points for the Knicks in their final home game of the season, which opened a home-and-home series. Rookie Frank Ntilikina added a career-high 17 and Courtney Lee also had 17.
Sacramento, which was eliminated from the postseason on March 11, led by 14 points before being outscored 38-19 in the fourth quarter.
Reserves Gay, Ginobili and Bryn Forbes combined for 25 points in the fourth quarter. Forbes finished with 11 points total.
Willie Cauley-Stein led Sacramento with 25 points and 10 rebounds.
Detroit was without injured stars Andre Drummond and Blake Griffin for its home finale, but the Pistons still led by 17 in the first half. The margin was only three, however, at halftime, and Detroit managed only 38 points over the final two quarters.
Detroit is out of playoff contention, and Toronto had already wrapped up the top seed in the Eastern Conference. The Raptors played without Fred VanVleet and Serge Ibaka.
Luke Kennard led Detroit with 20 points and Reggie Jackson scored 16 with nine assists. Langston Galloway had 15 points on 7-of-8 shooting.
D'Angelo Russell had 21 points and 11 assists, and Spencer Dinwiddie scored 20 points for the Nets, who had not won three straight since April 1-4, 2017.
Former Net Sean Kilpatrick was one of seven players for the Bulls to score in double figures, tallying 16 points. Cameron Payne had 15 for Chicago, which has lost its last three games.
Brooklyn hit 18 3-pointers in its first game since falling one shy of the NBA record with 24 in a rout of Chicago on Saturday.
Crabbe celebrated his 26th birthday by going 8 of 11 from deep Monday.
at Minnesota 113, Memphis 94: Karl-Anthony Towns slammed his way to 24 points and grabbed 18 rebounds for the Timberwolves, who toughed out a victory over the Grizzlies to move one step closer to a long-sought spot in the playoffs.
Jeff Teague added 24 points and Jimmy Butler scored 15 points for the Timberwolves, who trailed by 10 points early before taking over against a depleted Grizzlies team that beat them 101-93 exactly two weeks ago in one of their worst losses of the season. Towns had five dunks to help ignite the crowd.
Ben McLemore had 18 points for the Grizzlies, who moved one loss closer to a prime lottery pick.
The Wolves entered the evening with more than just payback on the agenda. They had the opportunity to secure their first appearance in the playoffs since Kevin Garnett was patrolling the post with Latrell Sprewell as a wing man and Sam Cassell running the offense in 2004.
The Bucks leapfrogged Miami for sixth in the Eastern Conference. The Heat lost to Oklahoma City on Monday.
Milwaukee won its second straight game without Giannis Antetokounmpo, who is resting a sore right ankle. Both victories came against 50-loss teams.
Nikola Vucevic led Orlando with 17 points and 10 rebounds, while Bismark Biyombo had 14 points.
Bledsoe had 20 points, 12 rebounds and 11 assists for Milwaukee.
The Nuggets have won a season-high six straight games and a seventh, on Wednesday night in Minnesota, would clinch their first playoff berth since 2012-13.
Jokic scored 15 points and pulled down a season-best 20 rebounds and had 11 assists. Will Barton added 22 points, leading a comeback from an 11-point third-quarter deficit.
The Trail Blazers, who lost for the fourth consecutive time, were in it until the very end, but Jusuf Nurkic, who had 20 points and 19 rebounds, missed one of two free throws with 47 seconds left and Jamaal Murray sank two free throws with 30 seconds left to put Denver ahead 84-80. Damian Lillard, who led the Trail Blazers with 25 points, missed a 15-footer and Paul Millsap grabbed the rebound.
NEW ORLEANS 113, at CLIPPERS 100