Doncic had 36 points, 16 rebounds and 15 assists to post the 29th triple-double of his career, breaking a tie with Michael Jordan to move into 15th on the league's all-time list.
However, Doncic blamed himself for the loss, suggesting that he got caught up with his statistics after a spectacular first half.
"The second half, I played terrible," Doncic said. "That's on me, that game. I was being selfish a little bit because I had 30 points in the first half. That wasn't me in the second half. I've got to do way better in the second half. That's just on me. I've got to do way better."
Dallas, which was missing three starters and a total of six rotation players due to injuries and the NBA's health and safety protocols, trailed by 15 at the half despite Doncic's 30 points on 11-of-18 shooting. He finished the game 13-of-30 from the floor, including 6-of-11 from 3-point range, and had 10 of his 15 assists in the second half.
But Doncic said he was "taking some shots I shouldn't be taking" in the second half, adding that the team as a whole needs to play with better energy.
"We were all disappointed with our performances," said Mavs big man Kristaps Porzingis, who had 20 points, 8 rebounds and 2 blocks. "It is what it is. He always expects greatness from himself. I'm the same way. We have a lot of high-character guys that want to do the right thing on the court. It's a team game, so we have to find ways how to play for each other so we can feed off of each other's energy."
Doncic became only the fourth player in NBA history to record at least 35 points, 15 rebounds and 15 assists in a game and the youngest to do so. Oscar Robertson had five such performances. Wilt Chamberlain and James Harden each had one.
"The stats are spectacular," Mavs coach Rick Carlisle said. "I mean, 36, 16 and 15, it's phenomenal, but without a win, he won't be happy with it, either. Right now, we're entering the most difficult seven days of scheduling in Mavericks history. Individual stats are impressive, but we're in the business of trying to win games."