James Harden scored 28 points, Ivica Zubac had a double-double and Clippersbeat Luka Doncic and the Mavericks 109-97 to win their Western Conference playoff series opener Sunday in Los Angeles.

Harden hit 6 of 11 3-pointers and had eight assists. Zubac’s 20 points were a playoff career high to go with 15 rebounds. Paul George added 22 points. The fourth-seeded Clippers outdid the fifth-seeded Mavs at their own 3-point game, making 18 of 36 from long range to 10 of 33 for the visitors.

The Clippers had five players in double figures without Kawhi Leonard. The two-time NBA Finals MVP hasn’t played since March 31 because of inflammation in his surgically repaired right knee.

The teams were meeting in the playoffs for the third time in five years, with the Clippers having won both previous series.

Doncic had 33 points and 13 boards. Kyrie Irving added 31 points and seven rebounds, but the Mavs got little from their supporting cast.

Tatum’s triple-double powers Celtics: Jayson Tatum notched his first career playoff triple-double with 23 points, 10 rebounds and 10 assists to lead the Celtics past the Heat 114-94 to open their Eastern Conference first-round series.

Derrick White added 20 points and four assists for the top-seeded Celtics, who finished with six players in double-figures.

The Heat spoiled the Celtics’ NBA Finals dreams last season, jumping out to a 3-0 lead in the conference finals and then blowing them out in Boston in Game 7.

But the Celtics fed off the energy of the TD Garden crowd Sunday, knocking down 22 3-pointers and outscoring the Heat 31-14 in the third quarter. The Celtics’ lead grew as high as 34 points in the fourth.

Bam Adebayo scored 24 points for the the eighth-seeded Heat, who played for the second straight game without star Jimmy Butler following his right knee injury during the play-in round.

Nuggets start slow, take over: Unlike their crowd that drowned out the Lakers’ pregame introductions, the defending NBA champion Nuggets were a little late to the playoff party Saturday in Denver.

They turned up their offense and defense after a sputtering start, however, powering past the Lakers 114-103 behind Nikola Jokic’s 32 points and 12 rebounds in the West series opener, their ninth consecutive triumph over the Lakers.

After watching LeBron James score 19 first-half points, capped by a pull-up 3 from 32 feet in the final second that put the seventh-seeded Lakers up 60-57, the second-seeded Nuggets limited the NBA’s 39-year-old career scoring leader to nine points in the second half and didn’t allow him to even take a shot in the fourth quarter until just 1:20 remained.

James finished with 27 points and Anthony Davis had 32.

Two other Nuggets matched Jokic’s double-double — Jamal Murray (22 points, 10 assists) and Aaron Gordon (12 points, 11 boards) — and Michael Porter Jr. came close with 19 points and eight boards.

The Nuggets swept the Lakers in last season’s West finals.