KISSIMMEE, Fla. — When Luka Doncic arrived at the NBA bubble, one of the oldest basketball narratives was waiting for him: Rising stars must pay their dues in the postseason, learning to adjust to extra defensive attention and intensity.

A week ago, the Dallas Mavericks’ 21-year-old sensation hadn’t played a playoff game. What a week it has been, starting with Doncic setting an NBA record by scoring 42 points in his postseason debut Monday against the Los Angeles Clippers.

But “Playoff Luka” truly arrived Sunday, when the second-year guard posted 43 points, 17 rebounds and 13 assists and hit a buzzer-beating three-pointer to give the Mavericks a 135-133 overtime win in Game 4. No player in the history of the NBA playoffs has matched or exceeded Doncic’s totals in points, rebounds and assists in the same game, and he joined LeBron James, Oscar Robertson, Jerry West, Charles Barkley and Russell Westbrook as the only players to post a 40-point triple-double in the playoffs.

“He sees the game in 6G,” Mavericks Coach Rick Carlisle said. “It’s not 5G. It’s 6G, another level beyond what most people see it. Just a very, very special player. This game today was from another planet.”

As if outdueling Kawhi Leonard wasn’t impressive enough, Doncic upped the degree of difficulty by playing through a left ankle sprain that sidelined him down the stretch of a Game 3 loss. Doncic wasn’t cleared to play until shortly before Game 4, and he emerged afterward with a thick ice wrap around his left ankle and foot.

Despite the bum wheel, Doncic put on a show, especially down the stretch. He manipulated matchups and found seams in the defense like a playoff veteran, and he welcomed verbal exchanges with the Clippers.

“Big dawg,” Portland Trail Blazers guard Damian Lillard wrote on Twitter, a nod of approval from one late-game maestro to another. “A great player doing great things.”

On the final play of overtime, Doncic used a screen to free himself from Leonard and then went to work on Reggie Jackson, a smaller guard. Although he had just 3.7 seconds to work with, Doncic went through a series of feints, changing direction multiple times to set up a step-back three-pointer going to his left.

The game-winner came from 27 feet at the left angle, with Jackson getting a hand up late to contest. No matter: The shot rattled home as time expired, helping Dallas even the series at two games apiece.

“To be truthfully honest, I feel like he could have gotten a better shot,” Mavericks guard Trey Burke quipped. “But, hey man, he ain’t need it.”

Even though the shot came in a near-empty gym without fans at the ESPN Wide World of Sports Complex, Doncic was immediately mobbed by his teammates and a raucous celebration ensued. Already one of the game’s most expressive stars on the court, Doncic couldn’t hide a wide smile as he recalled his winner.

“I was just trying to make it,” he said. “I can’t explain the emotions, not only when the ball goes in but when I see the whole team running toward me. That was something special. One of the best feelings I’ve ever had.”

The Clippers, who had tried to bait Doncic and Kristaps Porzingis into confrontations earlier in the series, were left in stunned silence. With Patrick Beverley sidelined by a calf injury and Paul George struggling badly, the Clippers’ hopes to regain the series fall on Leonard’s shoulders. The reigning Finals MVP finished with 32 points, nine rebounds and four assists, but he missed a possible game-winner at the end of regulation and a potential go-ahead shot in the final minute of overtime.

That opened the door for Doncic, whose heroics led the no-nonsense Carlisle to evoke Hall of Famers Larry Bird and Jason Kidd as comparison points.

“Kidd and Bird, both of those guys are from the same fabric competitively,” Carlisle said, “in terms of their will to win and their resourcefulness to find ways to impact the game in unique forms. It’s not just about putting the ball in the basket; it’s about giving your teammates confidence.”

Perhaps Doncic’s first taste of the postseason has been aided by the bubble: He didn’t need to open the playoffs on the road or deal with hostile crowds. Perhaps this instant breakthrough was somewhat predictable, too. An obsessive basketball savant, Doncic has looked comfortable in Disney World’s hoops-only environment over the past month.

In just four games, Doncic has raised the bar and changed the story. “Can he do it in the playoffs?” has given way to “Can he pull off the upset against one of the NBA’s top contenders?”

For the Clippers, Doncic is pure danger. Dallas is playing with house money, and its Slovenian star faces no pressure. If the Mavericks exit in the first round, they still will have won everyone’s respect and plenty of new fans. If the Clippers fall, though, their power play for Leonard and George will have combusted in stunning fashion, and they will be regarded as the league’s biggest disappointments.

Had Doncic’s shot missed in overtime, the Clippers would be sitting pretty with a 3-1 lead and the Mavericks would be on the ropes. Instead, he delivered and found himself in a whirlwind of excitement. Doncic was so overwhelmed that he struggled for words when asked whether he had a favorite memory of watching a playoff game-winner.

“I don’t think I can remember one shot,” he said, amused by his own disorientation. “My feelings are not here right now. I’ll think about it and let you know next time.”