Josh Giddey's final-quarter triple treat in New Orleans has secured a 4-0 sweep and an eight-year NBA first for Oklahoma City.
The Thunder beat the Pelicans 97-89 on Tuesday (AEST), Giddey (14 points on four-of-six three-pointers) seizing the moment with three clutch triples in a defining fourth-term blitz.
The Australian guard had 21 points, eight rebounds and six assists in OKC's other road defeat of New Orleans, crucial contributions after a quiet game-one performance attracted criticism.
With a 4-0 series win, the Western Conference top seeds — the youngest squad to achieve that feat and youngest to win a playoff series — advance to the second round for the first time since 2016.
"There's just some arenas where you feel good and this is probably one of them for me," the 21-year-old Victorian said.
"These are the moments you want to be in. Not even the last 18, 24 months; all the work you do before that gets you to this point and you can't shy away when you get to this stage."
Giddey said a focus on holding his own defensively had kept the door ajar for his final-quarter fireworks after NBA coach of the year Mark Daigneault had benched Giddey for the final minutes of their tight game-one win.
"Teams will attack (defensive liabilities) … that's how you get played off the floor and I never wanted to be that guy," he said.
"I wanted to be on the floor in playoff moments."
The Thunder will next face either the No.4-seeded Los Angeles Clippers or Boomers wing Josh Green's fifth-seeded Dallas Mavericks — that series is tied 2-2.
Jalen Williams and Shai Gilgeous-Alexander both had 24 points for Oklahoma City, who trailed by five in the fourth quarter before seizing control with a combination of stifling defence and opportunistic shooting.
A Giddey three-pointer tied it at 80-80 and ignited their 18-2 run, capped by Williams' second-chance triple, that put the Thunder up 93-82 with 3:08 left.
The Pels, who played the entire series without star power-forward Zion Williamson, never recovered.
In Denver, Jamal Murray (32 points) hit the game-winner for the Nuggets with three seconds on the clock, their 108-106 victory sending LeBron James's Los Angeles Lakers packing 4-1.
Nikola Jokic had 25 points, 20 rebounds and nine assists for the Nuggets, who had swept the Lakers in the first-round last season.
James had 30 points, 11 assists and nine rebounds. He turns 40 next year, with attention now switching to whether he takes up his player option this off-season.
In Miami, Derrick White scored a career-high 38 points as Boston beat the Heat 102-88 to take a 3-1 lead in their Eastern Conference series.
But it was a costly win, with Kristaps Porzingis going down in the first half with what the team said was a right calf injury.
Bam Adebayo finished with 25 points, 17 rebounds and five assists for Miami, who played again without injured starters Jimmy Butler (knee) and Terry Rozier (neck).
Boomers guard Patty Mills earned some extended court time for the Heat in an otherwise quiet playoffs campaign, scoring nine points in 22 minutes.
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