Gilgeous-Alexander produced a dazzling all-round performance to bag the 18th 40-point game of his career, overwhelming a shell-shocked Cavs line-up at the Paycom Center in Oklahoma City.

The 26-year-old Gilgeous-Alexander finished with 40 points, eight assists and three rebounds, the standout performance in a blowout that no one saw coming.

Luguentz Dort offered offensive support with 22 points, including six-of-nine from three-point range. Jalen Williams added 19 points.

Darius Garland led Cleveland's scoring with 20 points, while Donovan Mitchell was restricted to just eight points.

The result leaves Oklahoma City and Cleveland with identical records of 34-6 at the top of their respective conferences.

Gilgeous-Alexander sought to play down the significance of the victory after the final buzzer.

"Tonight was a good performance. We did the things we were supposed to do," the Canadian point guard told broadcaster TNT television.

"But for us, it was just another night of basketball, another night of competing together, another night of being competitive.

"It happened to be a hype game. It happened to be on TV. But for us, we're at home in front of the best fans in the NBA. We gave it our all and the outcome was the outcome."

Gilgeous-Alexander admitted the Thunder took satisfaction from handing out such a comprehensive defeat against a team that prior to Thursday had the best record in the league.

"It's the cream of the crop and obviously you want to test yourself against the best to find out where you really are," he said. "We tested ourselves and I think we passed."

- 'An avalanche' -

Cavs coach Kenny Atkinson blamed "uncharacteristic" defensive blunders for his team's loss.

"They imposed their will in every sense. Turned us over, and then we couldn't stop them. But it starts with the turnovers, which is uncharacteristic of us," Atkinson said.

"It was an avalanche and we really just never responded."

The Eastern Conference-leading Cavaliers had beaten the Thunder 129-122 last Wednesday in a hard fought battle in Cleveland.

Most analysts had anticipated another close duel in Thursday's rematch between two teams many expect to end up meeting in the NBA Finals in June.

But the Cavaliers never recovered after a first-quarter onslaught that saw the Thunder sprint to a 32-14 lead after a scorching 22-2 run.

Oklahoma City kept their foot on the pedal for the remainder of the first half, punishing a litany of defensive errors by Cleveland to take a commanding 75-49 lead at the break.

The Thunder forced 13 turnovers from the Cavaliers which were converted into 22 points in the first half.

The beatdown continued after half-time, with the Thunder stretching their advantage to 33 points early in the third quarter to lead 87-54.

The lead had increased to 38 points by the end of the third quarter, with Cleveland trailing 119-81.

That afforded Thunder coach Mark Daigneault the luxury of being able to rest most of his starters for the fourth quarter as the bench closed out the victory.

In other games, DeMar DeRozan finished with 31 points as the Sacramento Kings halted the second-placed Houston Rockets' five-game winning streak with a nailbiting 132-127 victory in California.

Malik Monk added 28 points and Domantas Sabonis scored 20 as the Kings improved to 21-20 in the Western Conference.

In Washington, Devin Booker scored 37 points and Kevin Durant added 23 as the Phoenix Suns overcame the Wizards 130-123.

In Detroit, the Indiana Pacers overpowered the Pistons 111-100 with 28 points from Myles Turner and 26 from Pascal Siakam.

The Los Angeles Clippers cruised to another dominant win with a 118-89 mauling of the Portland Trail Blazers.