Center Chet Holmgren poured in 30 points and pulled down 14 rebounds, and NBA Most Valuable Player Shai Gilgeous-Alexander added 20 points and 11 assists for the reigning champion Thunder, who notched a seventh straight victory to improve to 64-16 with two games left in the regular season.
Oklahoma City snagged the West's top seed for the third year running, and with the best overall record they'll have home court advantage throughout the playoffs.
"It's extremely important," said Holmgren, who added five assists, two steals and four blocked shots. "Just knowing that in the event of a game seven it's always going to be at home. We saw that in the playoffs last year twice, so it's extremely important.
"It's great to see that the hard work has paid off in one way, and now we've got more to do," Holmgren added.
OKC's win means the surging San Antonio Spurs are locked into the second seed in the West.
San Antonio cruised past the Portland Trail Blazers 112-101 despite the absence of superstar Victor Wembanyama -- who sat out with a bruised rib -- and Stephon Castle.
De'Aaron Fox scored 25 points to lead a balanced Spurs attack. Keldon Johnson scored 20 points off the bench and rookie reserve Carter Bryant contributed 17.
The Denver Nuggets tightened their grip on third place in the West, beating the Memphis Grizzlies 136-119 behind a triple-double of 14 points, 16 rebounds and 10 assists from Nikola Jokic.
Three-time MVP Jokic posted his 34th triple-double of the season, the 198th of his career, to help Denver win their 10th straight -- their first double-digit win streak of his tenure.
Jamal Murray scored 26 points to lead eight Nuggets players to score in double figures as Denver edged further ahead of the injury-hit Los Angeles Lakers for the third seed.
Eastern Conference top seeds Detroit welcomed star guard Cade Cunningham back to action with a 137-111 victory over the Milwaukee Bucks.
Cunningham, who had missed 11 games with a collapsed lung, scored 13 points and handed out 10 assists in just under 26 minutes on court.
Jalen Duren scored 21 points to lead the Pistons, who had seven players score in double figures.
The Pistons have locked up the top seed and home court advantage throughout the Eastern Conference playoffs, but coach J.B. Bickerstaff said the return of Cunningham and teammate Isaiah Stewart, sidelined since March 13th with a calf strain, was a welcome opportunity to build their fitness before the playoffs start on April 18th.
"There is no way to replicate NBA basketball," Bickerstaff said.
Cavs hold off Hawks
In Cleveland, Donovan Mitchell scored 31 points, Evan Mobley added 22 points and 19 rebounds and James Harden chipped in 21 points as the Cavaliers held off the Atlanta Hawks 122-116, denying the Hawks' bid to clinch a playoff berth.
The Cavs, who notched a fourth straight win, are assured of a top-four seed in the East and are chasing the New York Knicks for third.
The Hawks are fifth in the East, but they are just half a game ahead of sixth-placed Toronto and could still slip into the play-in tournament that will see the seventh- through 10th-placed teams battle for the last two playoff spots.
Nickeil Alexander-Walker scored 25 points, and Jonathan Kuminga added 24 off the bench for Atlanta, who cut an 18-point fourth quarter deficit to two but could get no closer.
The Orlando Magic kept their hopes of escaping the play-in alive with a fourth straight win, beating the Minnesota Timberwolves 132-120.