When Luka Doncic first stepped onto the AdventHealth Arena court Sunday afternoon, he hoped to prove to himself and the Dallas Mavericks' medical staff that he could play in Game 4 -- about 40 hours after spraining his left ankle.

Doncic received clearance to play and proceeded to deliver a historic performance, capping a 43-point, 17-rebound, 13-assist masterpiece with a buzzer-beating step-back 3-pointer to seal the Mavs' series-evening 135-133 overtime win over the LA Clippers.

"I can't explain the emotions I had," Doncic said. "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 ever had as a player. Just something special."

The effort of the 21-year-old Doncic, who led the Mavs to the franchise's biggest playoff comeback ever after Dallas trailed by 21 in the first half, certainly qualified as something special. According to research by Elias Sports Bureau, Doncic became the youngest player in NBA history to record a 40-point triple-double in the playoffs. It tied for the second-highest-scoring postseason triple-double in league history, behind a 51-pointer by then-Oklahoma City Thunder guard Russell Westbrook.

The only other time a player capped a 40-point playoff performance by hitting a make-it-or-lose buzzer-beater was when Chicago Bulls legend Michael Jordan hit "The Shot" over the Cleveland Cavaliers' Craig Ehlo in 1989.

"As soon as we saw that he was in the lineup, we knew we were going to get something special from him," said Mavs guard Seth Curry, who had 15 points on 6-of-9 shooting off the bench.

Doncic did it on a sprained left ankle without costar Kristaps Porzingis, who was a last-minute scratch because of right knee soreness. Porzingis' Game 5 status is to be determined.

"Look, we know this kid has got a flair for the dramatic," Dallas coach Rick Carlisle said. "He's a performer as well as a great player. He's a guy that lives for these moments and is completely fearless."

Doncic also displayed incredible toughness, considering that the sprained ankle forced him to leave the Mavs' Game 3 loss in the fourth quarter Friday, after he reentered the game but determined that he couldn't push off that leg. An MRI on Saturday confirmed that it was a relatively mild ankle sprain, but the Mavs were concerned that the quick turnaround between games would be problematic.

Doncic responded well to around-the-clock treatment overseen by Mavs director of player health and performance Casey Smith and his staff, resulting in optimism that Doncic would be able to play Sunday afternoon.

"The guys that you don't hear about behind [the scenes] did an amazing job with me yesterday," said Doncic, who joined Magic Johnson as the only players in NBA history with a pair of triple-doubles in their first four playoff games. "We were working almost the whole day. They were helping me out the whole time, whatever I needed. I obviously wasn't 100 percent, but I think I was good."

Doncic grimaced upon landing after a driving floater in the first quarter, noticeably limping and grabbing his ankle after getting back on defense. But that was about the only evidence during the game that his sprained ankle was bothering him. Doncic consistently dominated off the dribble, scoring 28 points in the paint and creating several of his assists by driving and collapsing the Clippers' defense.

Doncic rarely left the floor, playing 46 minutes, the most of any game in his NBA career.

"Listen, there was nothing that was going to keep him from staying in the game," Carlisle said. "He kept telling me that he was good, as many minutes as we needed him. I didn't even try to get him out before the quarter breaks. That would have been a fistfight, and I wasn't into that today. Look, we needed him out there. We needed him out there."

Doncic had 15 points, 9 rebounds and 7 assists in the first half to keep the Mavs in the game as Dallas sliced a 21-point deficit to a manageable eight points by halftime. Doncic dominated the third quarter, accounting for more points than the Clippers by a 25-19 margin, scoring 13 and dishing out five assists in the frame as the Mavs seized control of the game.

"He plays with a different type of passion," said Mavs guard Trey Burke, who scored 25 points on 10-of-14 shooting as a spot starter. "He don't back down from nobody. It don't matter who's talking to him, he's not going to back down. It kind of raises his level of play, to be honest. The guys that's talking to him, to be honest with you, that raises his level. Tonight, that's what happened. Obviously, it was a little chirpy on both sides.

"Luka just raised his level of play, just like a star should, and we followed behind it."

With Doncic resting early in the fourth quarter, the Mavs pushed their lead to 12 points. However, the clutch woes that have haunted Dallas all season reared their head late in regulation, as the Clippers outscored the Mavs by seven in the final five minutes to force overtime. According to ESPN Stats & Info, Doncic had been 0-of-10 this season on potential game-tying or go-ahead field goal attempts in the final minute of regulation or overtime.

He went 3-of-3 on such shots in overtime of Game 4.

Doncic tied the score with 50 seconds remaining after driving by Clippers star Kawhi Leonard and hitting a tough floater off the glass over Marcus Morris Sr. He gave the Mavs the lead with 19 seconds remaining when he attacked a mismatch against reserve guard Reggie Jackson, driving into the middle of the lane and finishing with a layup after a spin move. The Clippers regained the lead when Leonard (32 points, 9 rebounds, 4 assists) drove into the lane and kicked the ball to Morris for a corner 3.

After a timeout with 3.7 seconds remaining, Doncic caught the inbounds pass on the midcourt logo with Jackson on him again, a mismatch created when Leonard and Jackson switched following a screen. Doncic dribbled left, changed directions after going through his legs and crossed back over to his left before unleashing the 28-foot step-back that will be replayed for generations to come.

"When the shot left his hand, to be truthfully honest, I thought he could get a better shot," Burke said. "But hey, man, he ain't need it. He ain't need it. It's a big win that we're going to have to build off of."

The buzzer had sounded by the time the ball swished through the net, putting the exclamation point on Doncic's masterpiece. He celebrated by pounding his chest with his fist before being surrounded by his Mavs teammates and staffers.

Doncic has hit plenty of big shots in high-stakes situations before, having led Real Madrid and the Slovenian national team to titles at the highest levels of European competition. None, he said, compared to this bucket to beat the second-seeded Clippers and turn the series into a best-of-three.

Said Doncic: "That was one of the best feelings ever."