"I remember that day," Doncic said Sunday. "Normally, I was never nervous before a game. That game, I was nervous, for sure. It was something special for me. Just growing up, I used to watch him a lot. It was something special that game."
Afterward, the 19-year-old Slovenian who was drafted No. 3 overall in 2018, raced to the Lakers locker room to secure James' game-worn jersey and a signature.
More than a year later, Doncic again entered Staples Center to face his childhood idol, this time as the reigning NBA Rookie of the Year, and he sealed a 114-100 win that snapped the Los Angeles Lakers' 10-game winning streak on James' home court.
Doncic finished with 27 points, including 21 after halftime, 10 assists, nine rebounds and three steals. But the bulk of his damage came in the game-turning third quarter.
In that frame, Doncic tallied 16 points and five assists, keying a 28-5 Mavericks run.
The highlight of the night came when Doncic drilled a deep, step-back 3-pointer over James in the fourth quarter, with Mavericks legend Dirk Nowitzki looking on from a courtside seat.
"He hit a couple of hellacious shots that there's just a small handful of guys in the whole world can hit," Mavericks coach Rick Carlisle said of Doncic. "LeBron James is one of them. He's one of them. Those step-back 30-footers -- it's hard to describe how difficult of a shot it is and how easy he makes it look."
Doncic edged James again Sunday night. The 20-year-old posted his 16th career game with at least 25 points and 10 assists, breaking a tie with James for the most by a player before his 21st birthday in NBA history, according to ESPN Stats & Information research.
"It's a great win that means a lot to us," Doncic said. "It shows that we can play against big teams too. We just need to keep it rolling."
Luka, Mavericks snap Lakers' win streak
Luka Doncic scores 27 points and finishes a rebound shy of a triple-double as the Mavericks top the Lakers 114-100, snapping Los Angeles' 10-game win streak.
Luka hits step-back 3 over LeBron
With LeBron James guarding, Luka Doncic steps back and hits a deep 3-pointer in the fourth quarter.