Chet Holmgren had 24 points and 12 rebounds as the Oklahoma City Thunder routed the Los Angeles Lakers 108-90 in Game 1 of their NBA Western Conference semi-final series.

Shai Gilgeous-Alexander and Ajay Mitchell each added 18 points for the Thunder in Oklahoma City on Tuesday night (Wednesday AEST).

The defending champions improved to 5-0 in the playoffs, despite missing 2025 All-Star Jalen Williams with an injured left hamstring.

The Thunder, who shot 49.4 per cent from the field and made 13 of 30 three-pointers, host Game 2 on Thursday (Friday AEST).

Los Angeles struggled to find offence without Luka Doncic, who has missed the past month with an injured left hamstring.

LeBron James scored 27 points and Rui Hachimura 18 for the Lakers. Austin Reaves, who averaged 23.3 points in the regular season, was held to eight on 3-for-16 shooting.

Oklahoma City, who won all four regular-season match-ups by an average of 29.3 points, held the Lakers to 41.7 per cent shooting and forced 17 turnovers.

The Lakers ran out to an early 7-0 lead, with James scoring five. Eventually, the Thunder shook off the rust from an eight-day break and went up 31-26 at the end of the first quarter, despite 12 points from James.

Holmgren's two-handed alley-oop dunk on a lob from Isaiah Hartenstein put the Thunder up 48-39. Lakers forward Jarred Vanderbilt injured the pinkie finger on his right hand on the play, left the game and did not return.

Oklahoma City led 61-53 at halftime, despite 16 points from James.

Mitchell, who started in Williams' place, made a corner three-pointer and was fouled by Marcus Smart in the final minute of the third quarter. His free throw put the Thunder up 84-72, a score that held up until the end of the period.

Alex Caruso's fast-break dunk early in the fourth put Oklahoma City up 88-73, and they maintained control from there.

In Detroit, Cade Cunningham scored 23 points and Tobias Harris had 20 as the Pistons beat the Cleveland Cavaliers 111-101 in Game 1 of their second-round series.

Duncan Robinson added 19 points for the top-seeded Pistons, who ended an NBA record-tying 12-game post-season losing streak against a single opponent, a drought that dated back to the 2007 Eastern Conference finals.

Cleveland's Donovan Mitchell bagged 23 points, ending his NBA-record streak of scoring 30-plus points in nine straight series openers.

James Harden had 22 points for the No.4-seeded Cavs, who pulled into a tie midway through the fourth quarter after trailing for most of the night and by as much as 18 points.

Game 2 is on Thursday night (local time) in Detroit.

The Pistons won the Central Division this year by eight games ahead of the defending champion Cavs.

Detroit earned 60 victories and the top seed in the East just two years after losing 68 games and setting a single-season NBA record with 28 straight losses.

The Pistons rallied from a 1-3 deficit in the first round against Orlando to advance in the playoffs for the first time since 2008.

Cleveland outlasted Toronto in seven games to reach the second round for the third straight year.